1. Basic Computer Science

Foundation Course in Information Technology Outsourcing: Basic Computer Science UNIT - 1: BASICS OF COMPUTER SCIENCE Structure 1.0 Learning Objectives 1.1 Introduction 1.2 computer History 1.3 Fundamentals of computers 1.3.1 Computer components 1.3.2 Memory types 1.3.3 Number system 1.4 Internet Basics 1.4.1 Intranet 1.4.2 Extranet 1.4.3 Websites 1.4.4 Email 1.5 Computer Security Basics 1.5.1 The CIA Triad 1.6 Summary 1.7 Glossary 1.8 References 1.0 LEARNING OBJECTIVES After studying this unit, you will be able to: ● Explain computer hardware basics ● State computer memory types ● Explain the usage of the internet ● Illustrate computer security Page 1 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science 1.1 INTRODUCTION Computer Science includes a vast array of topics like the development and application of computer technology (hardware and software), information technology, cyber threat, security, etc. A computer is a machine capable of performing arithmetic and logical operations sequentially. It can store, process, and retrieve data. Computers are machines that perform tasks or calculations according to a set of instructions, or programs. The first fully electronic computers, introduced in the 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today's computers are amazing. Not only are they thousands of times faster, but they can also fit on your desk, on your lap, or even in your pocket. 1.2 COMPUTER HISTORY The history of computers is an interesting journey with numerous advancements at every stage. Some of the major milestones have been defined hereunder. The concept of a computer did not materialize overnight. Just as the growth and development of mature biological species normally took place over the ages, the computer also took thousands of years to mature. Ancient people used stones for counting or made scratches on a wall or tied knots in a rope to record information. But all these were manual computing techniques. Attempts had been going on for developing faster computing devices and the first achievement was the abacus, the pioneer computing device used by man. Let us take a look at the development of the computer through various stages. ABACUS Around 3000 years before the birth of Jesus Christ, the Mesopotamians quite unknowingly laid the foundation of the computer era. They discovered the earliest form of a bead-and wire counting machine, which Page 2 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science subsequently came to be known as an abacus. The Chinese improved upon the abacus so that they could count and calculate fast. Figure 1.1: Abacus An abacus consists of beads divided into two parts that can be moved on the rods of the two parts (Figure 1.1). Addition and multiplication etc. of numbers is done using the place value of the digits of the numbers and position of beads in the abacus. NAPIER’S ‘LOGS’ AND ‘BONES’ Fig 1.2 Napier’s Bones John Napier (1550-1617) developed the idea of Logarithm. He used ‘logs’ to transform multiplication problems into addition problems. Napier’s logs later became the basis for the well-known invention-the computing machine known as the ‘slide rule’ (invented in 1662). Napier also devised a set of numbering rods known as Napier’s bones (Fig 1.2). He could perform both multiplication and division with these ‘Bones’. The idea of the logarithm, developed in 1614, notably reduced the tedium of repetitive Calculations Page 3 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science PASCAL’S ADDING MACHINE In 1642, Blaise Pascal, a French mathematician, invented a machine made up of gears that were used for adding numbers quickly. This machine was named Adding Machine and was capable of addition and subtraction. It worked on the clockwork mechanism principle. The adding machine consisted of numbered toothed wheels having unique position values. The rotation of wheels controlled the addition and subtraction operations. This machine was capable of carry-transfer automatically. Figure 1.3 Pascal machine LEIBNITZ’S CALCULATOR Figure1.4 Leibnitz’s Calculator Gottfried Leibnitz, a German mathematician, improved an adding machine and constructed a new machine in 1671 that was able to perform multiplication and division as well. This machine performed multiplication through repeated addition of numbers. Leibnitz’s machine used a stepped cylinder each with nine teeth of lengths instead of the wheels used by Pascal. Page 4 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science JACQUARD’S LOOM Joseph Jacquard manufactured punched cards at the end of the American Revolution and used them to control looms in 1980. Thus the entire control weaving process was automatic. The entire operation was under a program’s control. With the historic invention of punched cards, an era of storing and retrieving information started that greatly influenced the later inventions and advancements. BABBAGE’S DIFFERENT ENGINE Figure1.5 Babbage’ Difference Engine Charles Babbage a professor of mathematics developed a machine called the Difference Engine in the year 1822. This machine was expected to calculate logarithmic tables to a high degree of precision. The difference engine was made to calculate various mathematical functions. The machine was capable of polynomial evaluation by finite difference and its operation was an automatic multistep operation. BABBAGE’S ANALYTICAL ENGINE In 1833, Charles Babbage started designing an Analytical Engine which was to become a real ancestor of the modern-day computer. With the methodical design of his Analytical Engine, Babbage meticulously established the basic principles on which today’s computers work. The Analytical Engine was Page 5 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science capable of performing all four arithmetic operations as well as comparison. It had several features startlingly similar to those in today’s electronic computers. He included the concept of the central processor, storage area, memory and input-output devices in his design. The two revolutionary innovations incorporated in the Analytical Engine were comparisons and modification of stored information. The first innovation enabled the machine to compare quantities and then decide which of the instruction sequences to follow. The second permitted the results of a calculation to change numbers and instructions already stored in the machine. Owing to the lack of technology of the times, Analytical Engine was never built. Its design remained conceptual. See Figure 1.6 of Babbage’s Analytical Engine and Figure 1.7 Charles Babbage (The Father of Modern Computer) Figure 1.7 Charles Babbage Two great inventions – The Difference Engine and Analytical Engine earned Charles Babbage the title ‘Father of Modern Computers’ – a fitting tribute to him. HOLLERITH’S MACHINE In 1887, an American named Herman Hollerith (1869-1926) fabricated what was dreamt of by Charles Babbage. He fabricated the first electromechanical punched-card tabulator that used punched cards for input, output and instructions. This machine was used by the American Department of Census to compile their 1880 census data and was able to Page 6 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science complete compilation in 3 years which earlier used to take around 10 years. (Figure 1.8) MARK Prof. Howard Aiken (1900-1973) in the U.S.A. constructed in 1943 an electromechanical Computer named Mark-I which could multiply two 10- digit numbers is 5 seconds-a record at that time. Mark-I was the first machine that could perform according to preprogrammed instructions automatically without any manual interference. This was the first operational general-purpose computer. 1.3 FUNDAMENTALS OF COMPUTER SYSTEM The computer is a device that transforms data into meaningful information. Data can be anything like marks obtained by you in various subjects. It can also be the name, age, sex, weight, height, etc. of all the students in a class. A user can also be defined in terms of the functions it can perform. A computer can i) accept data, ii) store data, iii) process data as desired, iv) retrieve the stored data as and when required and v) print the result in the desired format. The major characteristics of a computer are high speed, accuracy, diligence, versatility, and storage. Computer System Page 7 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Data processing involves the following three activities – ⮚ Input of data ⮚ Processing of data ⮚ Giving output (i.e. management of output result) ⮚ In a computer system, data is arranged orderly and systematically. The term “computer” is derived from the Latin term “compute,” which means ‘to calculate.’ Initially, the computer system had been designed to calculate; it was intended to be a computing device. However, over some time, this device technically advanced; at present, it can perform a wide range of desirable works apart from data processing. The block diagram of the computer is shown in Fig. Computer Block Diagram The computer performs five major operations or functions irrespective of its size and make. These are 1) it accepts data or instruction by way of input, 2) it stores data, 3) it can process data as required by the user, Page 8 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science 4) it gives results in the form of output, and 5) it controls all operations inside a computer. We discuss below each of these operations. Input: this is the process of entering data and programs into the computer system. Control Unit (CU): The process of input, output, processing, and storage is performed under the supervision of a unit called 'Control Unit'. It decides when to start receiving data, stop it, store data, etc. It takes care of step- by-step processing of all operations inside the computer. Memory Unit: The computer is used to store data and instructions. Arithmetic Logic Unit (ALU): The major operations performed by the ALU are addition, subtraction, multiplication, division, logic, and comparison. Output: This is the process of producing results from the data for getting useful information. The ALU and the CU of a computer system are jointly known as the central processing unit (CPU). You may call the CPU the brain of any computer system. S.N Operation Description o. 1 Take Input The process of entering data and instructions into the computer system. Saving data and instructions so that they are 2 Store Data available for processing as and when required. 3 Processing Performing arithmetic and logical operations on Data data to convert them into useful information. Page 9 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science 4 Output The process of producing useful information or Information results for the user, such as a printed report or visual display. 5 Control the Directs the manner and sequence in which all of workflow the above operations are performed. Major Functions of Computer System Following are the core functions of a computer system − ● A computer accepts the command and/or data as the input given by the user. ● A computer follows the instructions and stores the data given by the user. ● A computer processes the data as per the instructions given by the user. ● A computer gives the desired results in the form of output. Salient Features of Computer System Following are the salient features of a Computer System − ● Automation − The operating system of a computer system is automatic, as no human intervention is required; simply you need to give the command, and then it will do the work automatically. ● Speed − Depending upon the power of the computer, it can perform, it can take Millions of instructions per second. ● Storage − A computer system can store an enormous quantity of data in different formats. The storage capacity of a computer system is normally expressed in terms of Kilobytes (KB), Megabytes (MB), Gigabytes (GB), or Terabytes (TB). ● Accuracy − The accuracy of a computer system is very high. Page 10 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science ● Versatility − A computer system is capable of performing a wide range of tasks. ● Diligence − A computer neither gets tired nor loses concentration. ● Reliability − As a computer system always gives accurate results; therefore, its reliability is very high. ● Vast memory − A computer system can have a wide range of memory that can recall the desired data at any point in time. 1.4.1 Memory types Memory is a necessary part of the computer. It is a basic need to store and analyze data and accordingly give responses to the commands inferred on the computer by the users. Memory is the storage section of the computer’s functioning. The information for immediate use and the computer hardware devices and their functioning is stored in the memory too. High-speed operations take place in the memory for the processing of information in the computer. Similar to the human brain, there are different types of memory storage available on the computer. With changing times and constant development in technology, memory is also upgraded. 1. Primary Memory This type of memory includes both the RAM (Random Access Memory) and the ROM (Read-Only Memory). It stores very small amounts of data and can be accessed very quickly when the computer is running on power mode. i. RAM (Random Access Memory) The data that is stored in the RAM can be accessed randomly. There is no particular order needed. It is the most expensive type of memory. It is very fast and quick but requires power to run and exchange data and share data that is stored in its memory. Whichever data is needed to be Page 11 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science processed imminently is moved to the RAM where the modification and accessing of the data is done quickly so that there is no waiting period for the CPU to start functioning. It improves the speed of the processing of the CPU and the different multiple commands given to it by the users. Whichever data becomes out of use is then moved to the secondary memory and the space in the RAM is freed for further processes. Two types of RAM are: a. DRAM Dynamic RAM is the commonly used RAM in computers. Unlike earlier times when the computers used to use single data rate (SDR) RAM, now they use dual data rate (DDR) RAM which has faster processing ability. DDR2, DDR3, DDR4 are the available versions of the DRAM each efficient according to their number. The compatibility of the DRAM with the operating system needs to be checked before any installation. b. SRAM Static RAM is faster than Dynamic RAM and therefore it is more expensive. It has a total of six transistors in each of its cells. Therefore, it is commonly used as a data cache within the CPU and in high-end servers. It helps in the speed improvements of the computer. ii. ROM (Read-Only Memory) Data can be only read and not written to it. It is a fast type of memory. It is a non-volatile type of memory. In case of no power, the data is stored in it and then accessed by the computer when power is turned on. It usually contains the Bootstrap code which is required for the computer to interact with the hardware systems and understand its operations and functions according to the commands given to it. In simpler devices used commonly, there is ROM in which the firmware data is stored to get them to function according to their need. 2. Secondary Memory Page 12 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science It is physically placed or located inside a separate storage device which is then connected to the computer for access. HDD and SSD are the most commonly used secondary memory devices in a computer normally. They are not as expensive as the RAM and ROM and are reasonably priced. Their read and write speed is also comparatively lower. Since it is a separate device altogether, it can preserve the data that is saved inside it without the need for power. The data exchanged and stored is first sent to the RAM and then to the CPU for further processing. They have the possibility of permanently storing the data and at the same time, you can easily use them anywhere and carry them along with you. Uses of Memory in a Computer Computer memory is one of the basic needs of the CPU and its functioning to run the computer as it should. Computer Memory speeds up the data processing which is done by the CPU (Central Processing Unit). Storage of temporary and permanent data is necessary for the computer to run its processes and also respond to the user commands by communicating with all the hardware devices that support the computer and its running. The efficiency of the computer needs memory as a basic amenity in its system. The better the memory; the faster the computer will function. Number systems The technique to represent and work with numbers is called the number system. The decimal number system is the most common. Other popular number systems include: 1. Decimal Number System 2. Octal Number System 3. Hexadecimal Number System ASCII Besides numerical data, the computer must be able to handle alphabets, punctuation marks, mathematical operators, special symbols, etc. that Page 13 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science form the complete character set of the English language. The complete set of characters or symbols is called alphanumeric codes. The complete alphanumeric code typically includes − ● 26 upper case letters ● 26 lower case letters Page 14 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science ● 10 digits ● 7 punctuation marks ● 20 to 40 special characters Now a computer understands only numeric values, whatever the number system used. So all characters must have a numeric equivalent called the alphanumeric code. The most widely used alphanumeric code is American Standard Code for Information Interchange (ASCII). ASCII is a 7-bit code that has 128 (27) possible codes. ISCII-ISCII stands for Indian Script Code for Information Interchange. IISCII was developed to support Indian languages on the computer. Language supported by IISCI includes Devanagari, Tamil, Bangla, Gujarati, Gurmukhi, Tamil, Telugu, etc. IISCI is mostly used by government departments and before it could catch on, a new universal encoding standard called Unicode was introduced. Unicode-Unicode is an international coding system designed to be used with different language scripts. Each character or symbol is assigned a unique numeric value, largely within the framework of ASCII. Earlier, each script had its encoding system, which could conflict with each other. 1.4 INTERNET BASICS Internet is a system that interconnects the different computer systems across the world. It uses the Internet protocol suite to link devices located in different corners of the world. The Internet system carries an extensive range of information resources and services including World Wide Web (WWW), telephony, electronic mail, etc. It uses standard internet protocols, such as TCP/IP and HTTP, etc. An internal web comprises all Hypertext Transfer Protocol (HTTP) nodes on a private network; for example, an organization’s LAN or WAN. Page 15 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Features of Internet Let us now discuss the features of the Internet. The features are described below − Accessibility An Internet is a global service and access to all. Today, people located in a remote part of an island or interior of Africa can also use the Internet. Easy to Use The software, which is used to access the Internet (web browser), is designed very simple; therefore, it can be easily learned and used. It is easy to develop. Interaction with Other Media Internet service has a high degree of interaction with other media. For example, News and other magazine, publishing houses have extended their business with the help of Internet services. Low Cost The development and maintenance cost of Internet service is comparatively low. Extension of Existing IT Technology This facilitates the sharing of IT technology by multiple users in organizations and even facilitates other trading partners to use. Flexibility of Communication Communication through the Internet is flexible enough. It facilitates communication through text, voice, and video too. These services can be availed at both organizational and individual levels. Security Last but not the least, the Internet facility has to a certain extent helped the security system both at the individual and national level with components such as CCTV camera, etc. Page 16 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Internet Software Internet Software comprises all the tools needed for networking through the computer. Following are a few important components of the Internet Software − ● Transmission Control Protocol/ Internet Protocol (TCP/IP) ● Dialer Software ● Interment Browser ● Internet Applications Internet applications are server-based applications. Following are a few Internet Applications ⮚ World Wide Web (WWW) ⮚ Electronic mail (e-mail) ⮚ File Transfer Protocol (FTP) ⮚ Telnet (i.e., log-in to the computer located remotely) ⮚ Internet Relay Chat (IRC) (Real-time video chatting) How does the internet work? The internet works with the help of clients and servers. A device such as a laptop, which is connected to the internet is called a client, not a server as it is not directly connected to the internet. However, it is indirectly connected to the internet through an Internet Service Provider (ISP) and is identified by an IP address, which is a string of numbers. Just like you have an address for your home that uniquely identifies your home, an IP address acts as the shipping address of your device. The IP address is provided by your ISP, and you can see what IP address your ISP has given to your system. A server is a large computer that stores websites. It also has an IP address. A place where a large number of servers are stored is called a data center. The server accepts requests sent by the client through a browser over a network (internet) and responds accordingly. To access the internet, we need a domain name, which represents an IP address number, i.e., each IP address has been assigned a domain name. Page 17 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science For example, youtube.com, facebook.com, paypal.com are used to represent the IP addresses. Domain names are created as it is difficult for a person to remember a long string of numbers. However, the internet does not understand the domain name, it understands the IP address, so when you enter the domain name in the browser search bar, the internet has to get the IP addresses of this domain name from a huge phone book, which is known as DNS (Domain Name Server). For example, if you have a person's name, you can find his phone number in a phone book by searching his name. The internet uses the DNS server in the same way to find the IP address of the domain name. DNS servers are managed by ISPs or similar organizations. Internet Working Once the server gets the request to provide information about a particular website, the data starts flowing. The data is transferred through the optical fiber cables in digital format or the form of light pulses. As the servers are placed at distant places, the data may have to travel thousands of miles through optical fiber cable to reach your computer. The optical fiber is connected to a router, which converts the light signals into electrical signals. These electrical signals are transmitted to your laptop using an Ethernet cable. Thus, you receive the desired information through the internet, which is a cable that connects you with the server. Page 18 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Furthermore, if you are using wireless internet using wifi or mobile data, the signals from the optical cable are first sent to a cell tower and from where it reaches your cell phone in the form of electromagnetic waves. The internet is managed by ICANN (Internet Corporation for Assigned Names and Numbers) located in the USA. It manages IP addresses assignment, domain name registration, etc. Data transfer is very fast on the internet. The moment you press enter you get the information from a server located thousands of miles away from you. The reason for this speed is that the data is sent in the binary form (0, 1), and these zeros and ones are divided into small pieces called packets, which can be sent at high speed. 1.4.1 Intranet An intranet is a computing network, based on the same techniques as the internet, but which can only be used by a specific group within an organization. In many companies, intranets have replaced the “blackboard” and allow access to data specific to the company, such as telephone lists, the list of absences, information about the company, etc. The objective of an intranet is to facilitate access to information for employees within the company. As a general rule, when you start the browser, the intranet also starts automatically. The information published on the intranet is confidential and usually reserved for employees. Small companies with full knowledge of the facts use other channels of communication for employees. The intranet is, therefore, more common in companies that have more staff. The advantages of an intranet: ● Information flows within the company are faster ● The risk of error is reduced Page 19 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science ● Work is facilitated because all departments in the company have access to the common database and do not need to consult different lists or records ● Some applications can even be automated ● There are numerous possible uses Intranet How the Intranet Works: Intranet comprises three components: a web server, an intranet platform, and applications. The web server is hardware that contains all the intranet software and data. It manages all requests for files hosted over the server and finds the requested files and then delivers them to the user's computer. Page 20 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Intranet Working The intranet platform, which is software, allows communication tools, collaboration apps, and databases to work seamlessly with each other. It is tailored to the specific needs of a business. The applications are required to enable users to work smoothly. They are the computing tools that allow users to do their work, communicate, coordinate with each other and retrieve and store information. Furthermore, the user who wants to access the intranet is required to have a special network password and should be connected to the LAN. A user who is working remotely can gain access to the intranet through a virtual private network (VPN) that allows them to sign in to the intranet to access the information. Disadvantages of Intranet: ● It may be costly to set up an Intranet due to hidden costs and complexity. ● If the firewall does not work properly or is not installed, it can be hacked by someone ● High-security passwords are required, which cannot be guessed by outside users ● There is always a fear of losing control over the intranet ● Sometimes document duplication may happen which can cause confusion among employees Page 21 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science ● You have to give access to multiple users, so you may find it hard to control this network. Examples of Intranet: Educational Intranet: It is generally found in a school, college, etc., For example, a school intranet is intended to allow teaching staff to communicate with each other and get information about upcoming updates such as exam dates, schools functions, holidays, etc. Real Estate Intranet: The intranet of a real estate company allows its sales team to have access to all important brochures, templates, forms that they may need to close a sale. Employees also remain up to date with important events like meetings, training, sessions, etc. It can also be used to share motivational messages with the team. Health Care Intranet: In the healthcare sector, in big hospitals, the Intranet helps health care professionals to work as a team to provide proper care and treatment to their patients. Doctors can share reports, treatment procedures, bills, and claims that can be settled easily without moving from one department to another department. IT Sector Intranet: In the IT sector three is always a lot of information that needs to be shared with all the employees in one go. It may be related to a project that needs to be completed within the given time frame, such as guidelines, terms and conditions, and rules that are to be followed while working on a project. Difference between Intranet and Internet: Page 22 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Internet Intranet It is a medium such as optical fiber cable It is a small, private network that connects billions of computers to as it belongs to a specific establish a worldwide network. organization. It has billions of users as it is a public It has limited users. network with a worldwide presence. It is not as safe as an intranet. It is a safer network than the internet. It can be assessed or used by anyone Only authorized persons can using internet-enabled devices, such as use this network. laptops, mobile phones, etc. It offers a wide range of information, It offers limited information such as news, blogs, websites, etc. related to its organization's work, policies, updates, etc. It is not owned by a single person or an It can be owned by a person organization. or an organization. 1.4.2 Website Website is a collection of related web pages that may contain text, images, audio, video, etc. The first page of a website is called a home page. Each website has a specific internet address (URL) that you need to enter in your browser to access a website. A website is hosted on one or more servers and can be accessed by visiting its homepage using Page 23 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science a computer network. A website is managed by its owner that can be an individual, company, or organization. The first website was introduced on 6 August 1991. It was developed by Tim Berners-Lee at CERN. As of January 2018, there were around 1.7 billion websites on the internet. What is the need for a website? A popular website is another name of success in modern times as today we are living in a digital world where people are spending most of their spare time on the internet browsing news, images, videos, and more. A website is the first thing that appears on the screen of your laptop when you search for a product or service, or any other information online. So, it is very important to have a website whether you are a businessman, organization, online store, etc. Let us understand how a website can help you grow your business! The benefits of having a website are as follows: 1. Cost-effective: The marketing of products and services through a website is less costly than print advertising, TV, and radio advertising. It also allows you to make changes related to your products and services such as you can edit products' specifications, features, discount offers, etc. 2. Broder demographic reach: A website can help your business reach people with diverse backgrounds throughout the world. 3. Business credibility: Having a website that is user-friendly and professional looking for your business makes people consider your business more credible than others who don't have a website to represent their businesses online. 4. 24/7 availability: You can keep your products available for sale around the clock through a website. Customers can buy anytime, and thus you can earn more profits than a traditional storefront. 5. Consumer convenience: It improves the shopping experience of your customers; they can buy your products from the comfort of their homes. Page 24 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science 6. Build customer rapport: Online presence helps you build and maintain a rapport among your customers. You can also introduce special offers or discounts for your loyal customers. 7. Improves productivity: It saves your time as you don't need to explain your products or services to each customer separately, as all the information is already available on the website. 8. Educate your customers: You can educate people about the benefits of your products and can show them how they are betters than the competitors' products. 9. Change location: You can move your business to another location without affecting your sales as customers still can find you through your website. 10. Grow manpower: You can post job openings for vacant positions and allow applicants to check job descriptions and apply online. 11: Personalized email address: It allows you to set up personalized email addresses for employees, companies, partners, etc. You can receive mails on these mail ids and reply accordingly. Furthermore, you can share offers, happy hours, updates, and can get feedback through email. 12. Improve customer service: It allows you to improve customer services such as you can share phone numbers to contact you, and display other relevant information such as order status, delivery status, refund or replacement procedure, etc. Types of Websites: A website can be of two types based on the type of web pages: ● Static Website ● Dynamic Website Static website Page 25 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science A static website, as the name suggests, is a website in which pages do not change or remain the same. It is the basic type of website that is easy to create, maintain, and host. You don't need web programming and database design to create a static website. Its web pages are coded in HTML. The codes are fixed for each page, so the information contained on the page does not change, and it looks like a printed page. However, changes can be made by changing the codes if required. You can think of it as a brochure for a business that has the same information for every user. So, all users see the same information irrespective of their location, interests, etc., when they open a particular page of a static website. In the case of a static website, the content or webpage is taken directly from the file stored in the server without requiring any interpreter (application software) to interact with a database to fetch data from the database. So, database and server-side scripting are not required in static websites. Benefits of a Static Website: ● It takes less time to create a static website. ● It is less costly to develop this website. ● The webpages are delivered at high speed by the servers. ● Hosting through dedicated servers is available at a low price. ● It is more secure than dynamic sites as it does not rely on CMS plugins and server-side scripting. Dynamic website A dynamic website is a collection of dynamic web pages whose content changes dynamically. It accesses content from a database or Content Management System (CMS). Therefore, when you alter or update the content of the database, the content of the website is also altered or updated. A dynamic website uses client-side scripting or server-side scripting, or both to generate the dynamic content. For example, when a browser sends a request to the server, the server contacts the application server with further interacts with the database server to fetch the content, which is customized as per the user's requests and requirements. For Page 26 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science example, a Facebook page may appear different to different users as per their friends' list, interests, location, etc. Benefits of a Dynamic Website: ● It is very quick and easy to make changes in a dynamic website as it is integrated with high-end programming. ● The web pages are easier to maintain despite being full of information and graphics. ● E-commerce sites are dynamic as they need to be impressive and have easy navigation from one page to other pages. ● It makes your site look professional. ● The users can get customized information as per their interests, needs, profile, etc. For example, facebook.com, flipkart.com, etc. Difference between Static Website and Dynamic Website: Static Website Dynamic Website As the name suggests, its web As the name suggests, the web page does not change in terms pages keep changing as per users' of design, content, etc. The requirements such as Facebook information or content remains profile pages and an E-commerce the same. site. So, the content does not remain the same. It mainly uses HTML and CSS It requires server-side scripting, and does not require server-side application server, and database to scripting, application server, and create and send dynamic webpages database. to the client. It has a limited number of pages. It may contain thousands of pages in the database. Page 27 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Its hosting cost is low, as HTML Its hosting cost is higher as dynamic files need less space on the pages need more space on the server. server. It requires low maintenance. It requires high maintenance. It loads quickly as it involves the It takes more time to load due to the use of mark-up languages to more processing time. create a webpage. It lacks the Content It makes use of the Content management feature. Management Feature. The content of the webpage The webpage content can be cannot be changed during changed during runtime. runtime. It does not require interaction Interaction with the database occurs. with a database. It is more secure or has fewer It is less secure and may get hacked chances of it getting hacked as easily as it uses many plugins and it doesn't use plugins. content sources. It is more reliable, e.g., whenever It is less reliable, as it may go down the server is down, it is for hours if the server breaks down redirected to other nearby nodes. Page 28 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Types of Websites based on their purpose, target audience, etc. 1. Blog: It is a type of website that provides information or in which posts are added regularly in reverse chronological order, latest post or entries on top of the main page, and old ones towards the bottom. A blog is usually owned by a single person or a small group of people. The content in a blog is written in an informal or conversational style and can be focused on one subject or a wide range of related subjects. Furthermore, the posts are organized into categories if required, e.g., posts that provide similar information can be kept in a separate category. The content of a blog is generally referred to as a blog post, and it generally appears as posts on a streaming page. The information is regularly updated in a blog, e.g., articles, photos, and videos are added daily to keep readers engaged and increase the traffic to the blog. It also allows readers to leave a comment about the posts. 2. E-commerce: These types of websites are like online shops where people can buy products through online payment from the comfort of their home, office, etc. Anyone who wants to sell products online can create an E-commerce site instead of investing in setting up a traditional brick-and- mortar shop. 3. Informational: These websites are created to provide free online information to users, e.g., tutorials, news, general knowledge-based sites. Today, you don't need to visit libraries to read a book, newspaper, novel, etc. owing to the presence of lots of informational sites. 4. Online Community: These sites offer a platform to interact and share ideas with others through the internet. You can find people with similar interests and backgrounds and interact with them to fulfill your objectives which may include promoting a product or service, taking feedback about your products, or asking questions related to a survey. 5. Social Media: These sites are created to provide users a platform where they can build their profiles with a lot of features such as creating a friend list, sending and accepting friend requests, sending messages, Page 29 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science creating and joining groups, and sharing information with others users, comment on others' post, pictures, videos, etc. 6. Brochure: It is the simplest type of website which comprises a few pages. It is used by small businesses to have a simple online presence or to provide an overview of their business. Such websites are generally static where the content does not change, i.e., the same information is displayed to all users. 7. Non-profit: The sites are created to raise money for social causes such as to provide free medical treatment to the poor, free basic education to children, free food to children to prevent malnutrition, etc. 1.4.3 Email: Email is a service that allows us to send messages in electronic mode over the internet. It offers an efficient, inexpensive, and real-time means of distributing information among people. E-Mail Address Each user of email is assigned a unique name for his email account. This name is known as E-mail address. Different users can send and receive messages according to the e-mail address. E-mail is generally of the form username@domainname. For example, [email protected] is an e-mail address where webmaster is a username and tutorialspoint.com is a domain name. ● The username and the domain name are separated by @ (at) symbol. ● E-mail addresses are not case-sensitive. ● Spaces are not allowed in e-mail addresses. E-mail Message Components E-mail message comprises of different components: E-mail Header, Greeting, Text, and Signature. These components are described in the following diagram: Page 30 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Email component E-mail Header The first five lines of an E-mail message are called an E-mail header. The header part comprises of following fields: ● From ● Date ● To ● Subject ● CC ● BCC From The From field indicates the sender’s address i.e. who sent the e-mail. Page 31 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Date The Date field indicates the date when the e-mail was sent. To The To field indicates the recipient’s address i.e. to whom the e-mail is sent. Subject The Subject field indicates the purpose of the e-mail. It should be precise and to the point. CC CC stands for Carbon copy. It includes those recipient addresses whom we want to keep informed but not exactly the intended recipient. BCC BCC stands for Black Carbon Copy. It is used when we do not want one or more of the recipients to know that someone else was copied on the message. Greeting The greeting is the opening of the actual message. Eg. Hi Sir or Hi Guys etc. Text It represents the actual content of the message. Signature This is the final part of an e-mail message. It includes the Name of the Sender, Address, and Contact Number. Advantages E-mail has proved to be a powerful and reliable medium of communication. Here are the benefits of E-mail: ⮚ Reliable Page 32 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science ⮚ Convenience ⮚ Speed ⮚ Inexpensive ⮚ Printable ⮚ Global ⮚ Generality Disadvantages Apart from several benefits of E-mail, there also exist some disadvantages as discussed below: ⮚ Forgery ⮚ Overload ⮚ Misdirection ⮚ Junk ⮚ No response Forgery-E-mail doesn’t prevent forgery, that is, someone impersonating the sender since the sender is usually not authenticated in any way. Overload-Convenience of E-mail may result in a flood of mail. Misdirection-It is possible that you may send an e-mail to an unintended recipient. Junk-Junk emails are undesirable and inappropriate emails. Junk emails are sometimes referred to as spam. No Response-It may be frustrating when the recipient does not read the e-mail and respond regularly. 1.5 COMPUTER SECURITY BASICS Computer security is the protection of computer systems and information from harm, theft, and unauthorized use. It is the process of preventing and detecting unauthorized use of your computer system. There are various types of computer security which is widely used to protect the valuable Page 33 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science information of an organization. One way to ascertain the similarities and differences among Computer Security is by asking what is being secured. For example, ● Information security is securing information from unauthorized access, modification & deletion ● Application Security is securing an application by building security features to prevent Cyber Threats such as SQL injection, DoS attacks, data breaches, etc. ● Computer Security means securing a standalone machine by keeping it updated and patched ● Network Security is by securing both the software and hardware technologies ● Cybersecurity is defined as protecting computer systems, which communicate over the computer networks It’s important to understand the distinction between these words, though there isn’t necessarily a clear consensus on the meanings and the degree to which they overlap or are interchangeable. So, Computer security can be defined as controls that are put in place to provide confidentiality, integrity, and availability for all components of computer systems. Let’s elaborate on the definition. 1.6.1 The CIA Triad Computer security is mainly concerned with three main areas: The CIA Triad Page 34 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science ● Confidentiality is ensuring that information is available only to the intended audience ● Integrity is protecting information from being modified by unauthorized parties ● Availability is protecting information from being modified by unauthorized parties In simple language, computer security is making sure information and computer components are usable but still protected from people or software that shouldn’t access it or modify it. Computer security threats Computer security threats are possible dangers that can hamper the normal functioning of a computer. In the present age, cyber threats are constantly increasing as the world is going digital. The most harmful of computer security threats are: Viruses Viruses A computer virus is a malicious program that is loaded into the user’s computer without the user’s knowledge. It replicates itself and infects the files and programs on the user’s PC. The ultimate goal of a virus is to ensure that the victim’s computer will never be able to operate properly or even at all. Computer Worm Page 35 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science Computer Worm A computer worm is a software program that can copy itself from one computer to another, without human interaction. The potential risk here is that it will use up your computer’s hard disk space because a worm can replicate in great volume and with great speed. Phishing Phishing Disguising as a trustworthy person or business, phishers attempt to steal sensitive financial or personal information through fraudulent email or instant messages. Phishing is unfortunately very easy to execute. You are deluded into thinking it’s legitimate mail and you may enter your personal information. Botnet Botnet Page 36 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science A botnet is a group of computers connected to the internet, that have been compromised by a hacker using a computer virus. An individual computer is called a ‘zombie computer’. The result of this threat is the victim’s computer, which is the bot that will be used for malicious activities and a larger scale attack like DDoS. Rootkit Rootkit A rootkit is a computer program designed to provide continued privileged access to a computer while actively hiding its presence. Once a rootkit has been installed, the controller of the rootkit will be able to remotely execute files and change system configurations on the host machine. Keylogger Keylogger Also known as a keystroke logger, keyloggers can track the real-time activity of a user on his computer. It keeps a record of all the keystrokes made by the user keyboard. Keylogger is also a very powerful threat to steal people’s login credentials such as username and password. These are perhaps the most common security threats that you’ll come across. Apart from these, there are others like spyware, wabbits, Page 37 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science scareware, bluesnarfing, and many more. Fortunately, there are ways to protect yourself against these attacks. Why is Computer Security Important? In this digital era, we all want to keep our computers and our personal information secure and hence computer security is important to keep our personal information protected. It is also important to maintain our computer security and its overall health by preventing viruses and malware which would impact the system performance. Computer Security Practices Computer security threats are becoming relentlessly inventive these days. There is much need for one to arm oneself with information and resources to safeguard against these complex and growing computer security threats and stay safe online. Some preventive steps you can take include: ⮚ Secure your computer physically by: ⮚ Installing reliable, reputable security and anti-virus software ⮚ Activating your firewall, because a firewall acts as a security guard between the internet and your local area network ⮚ Stay up-to-date on the latest software and news surrounding your devices and perform software updates as soon as they become available ⮚ Avoid clicking on email attachments unless you know the source ⮚ Change passwords regularly, using a unique combination of numbers, letters, and case types ⮚ Use the internet with caution and ignore pop-ups, drive-by downloads while surfing ⮚ Taking the time to research the basic aspects of computer security and educate yourself on evolving cyber-threats Perform daily full system scans and create a periodic system backup schedule to ensure your data is retrievable should something happen to your computer. Apart from these, there are many ways you can protect Page 38 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science your computer system. Aspects such as encryption and computer cleaners can assist in protecting your computers and their files. Unfortunately, the number of cyber threats is increasing at a rapid pace and more sophisticated attacks are emerging. So, having a good foundation in cybersecurity concepts will allow you to protect your computer against ever-evolving cyber threats. 1.6 SUMMARY ● Computer Science is one of the disciplines of modern science about the various aspects of computer technologies, their development, and their applications in the present world. ● Computer Science includes a wide range of topics such as the development of Computer Technology (hardware and software), application of Computer technology ● Computers can connect to different locations using the Internet. ● Computer software that performs a task or set of tasks, such as word processing or drawing. Applications are also referred to as programs. ● Computer uses Internet Software comprises of all the tools needed for networking. ● Computer security is required for preventing damage to the hardware. 1.7 GLOSSARY ● Application: Computer software that performs a task or set of tasks, such as word processing or drawing. Applications are also referred to as programs. ● ASCII: American Standard Code for Information Interchange, an encoding system for converting keyboard characters and instructions into the binary number code that the computer understands. Page 39 of 40 All Rights Reserved. Vol. TLE001/03-2022

Foundation Course in Information Technology Outsourcing: Basic Computer Science ● Bandwidth: The capacity of a networked connection. Bandwidth determines how much data can be sent along the networked wires. Bandwidth is particularly important for Internet connections since greater bandwidth also means faster downloads. ● Binary code: The most basic language a computer understands, it is composed of a series of 0s and 1s. The computer interprets the code to form numbers, letters, punctuation marks, and symbols. 1.8 REFERENCES ● https://edu.gcfglobal.org/en/computerbasics/ ● https://www.uc.edu/webapps/af/hr/CUSTOMGUIDE/content/conten t/computerbasics.pdf ● https://teamtreehouse.com/library/computer-basics ● https://www.nist.gov/itl/smallbusinesscyber/cybersecurity-basics Page 40 of 40 All Rights Reserved. Vol. TLE001/03-2022