Internet Services-Notes

INTERNET SERVICES

What is Internet ▪ Internet stands for “International Network” ▪ Largest computer network in the world connecting millions of computers. ▪ Millions of users connected to each other worldwide via Internet. ▪ The use of Internet is inexplicable, both in our lives as well as society. ▪ It is a major medium of communication that offers services in all fields. ▪ The Internet is a network, or system, that connects millions of computers worldwide. ▪ It was one of the greatest inventions of the 1900s.

History of Internet ▪ The timeline of the Internet actually traces all the way back to the Vietnam War era: 1969, to be exact. ▪ The internet was developed in the United States by the \"United States Department of Defense Advanced Research Projects Agency\" (DARPA). ▪ It was first connected in October, 1969, and was called ARPANET. ▪ The World Wide Web was created at CERN in Switzerland in 1990 by a British (UK) man named Tim Berners-Lee. ▪ In India, Internet services started on 15th August 1995 through a government owned company called VSNL

Basic Terms Related To Internet ▪ World Wide Web -The World Wide Web (\"WWW\" or \"The Web\") is the part of the Internet that contains websites and webpages. It was invented in 1989 by Tim Berners-Lee at CERN, Geneva, Switzerland. ▪ URL(Uniform Resource Locator) Uniform Resource Locator (URL) is another name for a web address. URLs are made of letters, numbers and other symbols in a standard form. A URL has two main components: 1.Protocol identifier: For the URL http://example.com, the protocol identifier is http. 2.Resource name: For the URL http://example.com, the resource name is example.com. Note that the protocol identifier and the resource name are separated by a colon and two forward slashes. ▪ Website-A group of World Wide Web pages usually containing links to each other and made available online by an individual, company, or organization. ▪ Webpage-A page of written material and pictures that is shown on a Web site.

Basic Terms Related To Internet ■ ISP(Internet Service Provider) An Internet service provider, or ISP, maintains, installs and provides internet connection to residential or commercial areas. Examples-Airtel,Reliance,Tata,BSNL etc ■ Web Browser- A web browser (commonly referred to as a browser) is a software application for accessing information on the World Wide Web. Examples:Internet Explorer,Google Chrome,Mozilla Firefox,Safari,Opera.

Advantages of Internet ■ Communication- The Internet can allow a person to communicate with people in any part of the world, via the Internet or email, without leaving their room. ■ Information -Secondly, information is the most significant advantage that the Internet has to offer. The Internet is a treasure trove of practical knowledge. Any kind of information on any subject is available on the Internet. ■ Education Online-With the Internet, students can find their time to learn new things for your school projects and even topics they are interested in. Use your time to do this and other things. ■ Online Shopping-Through the Internet, shopping is gaining full support for the Internet. You have websites that sell a wide variety of products online and all financial transactions can be done on the Internet ■ Make Life Easy- The Internet has made life very convenient. With many online services, you can now do all of your transactions online.

Disadvantages of Internet ■ Spending more time online-some students spend more time online. Students are more likely to neglect their studies. If the cinema’s grip is so secure, even the elderly may ignore some of their essential work ■ Causing Anonymity-One more disadvantage of the Internet is that it allows anonymity for a large number of people who can access various websites, forums, and chat rooms. It has allowed unruly people to take advantage of innocent people many times and abuse their trust. ■ Kids avoiding outdoor activities-There are number of games available on the Internet that led many children to avoid all outdoor activities. In the absence of physical activity, children are more susceptible to many diseases associated with lifestyles

POPULAR INTERNET SERVICES

Search Engines ■ Internet search engine is a software that searches varies web pages on the World Wide Web(WWW). ■ World Wide Web (WWW) or simple web is a means of accessing and sharing information over the Internet. It contains millions of documents, called web pages. ■ To search Information : 1.A user types the description of the information using the user interface of the search engine. 2.The search engine then searches the requested information on the WWW and returns the results to the user.

E-Mail ■ E-Mail stands for Electronic Mail. ■ E-Mail is a rapid and productive means of communication. ■ It is faster than Paper Mail . ■ Unlike telephone, the persons communicating with each other need not to be available at the same time. ■ Unlike fax documents , Email documents can be stored in a computer and be easily edited using editing programs.

Chatting ■ Internet provides a facility to exchange typed-in messages online with people all over the world . ■ Instant Messaging , or IM is also a real time online communication with a selected group of people. ■ For Example- Whatsapp, ChatOn, G-talk etc

Internet Free Calls ■ Internet Free Calls: Internet provides a facility to make free voice calls to anyone across the world. ■ You can make free calls at much lower rates to anywhere in the world after installing particular software or applications which provides these services. ■ For Example- Skype, Tango, Viber, Google Hangouts, whatsapp etc.

Video Conferencing ■ Video Conferencing is a live telecommunication between two or more people at different locations. ■ It is an alternative to face-to-face meetings . ■ It usually involves audio, video and data. ■ Devices Required For Video Conferencing 1. Webcams 2. Microphones 3. Speakers 4. Visual Display 5. User Interface 6. Control System

Social Networking Sites ■ Social Networking Sites or SNSs are used to build online communication to share ideas, activities, events and exchange files, pictures, videos etc. ■ Facebook, Twitter are some of the very popular Social Networking Sites. ■ These sites are used by the people almost everyday for chatting,playing games and staying connected with each other.

E-Commerce ■ E-commerce or Electronic Commerce is a very important service provided by internet for financial transactions. ■ Different types of goods can be purchased and sold from ■ anywhere in the world through E-commerce. ■ Online banking , trading of stocks/bonds , ticket booking etc, also come under E- commerce. ■ The mode of payment for such transactions is a Credit card, Debit Card and Net Banking. ■ Amazon.com and Flipkart.com are the market leaders in online shopping in the world.

E-Learning ■ E-Learning means “Electronic Learning”. ■ Learning with the use of technology that enables the people to learn anytime anywhere. ■ Example: Khan Academy, W3 Schools

Online Banking ■ E-Banking stands for “Electronic Banking”. ■ It is the way of performing bank transactions using Internet. ■ It enables customers to perform all routine transactions such as account transfers, balance enquiries, bill payments etc.

NETWORK TOPOLOGY The way in which devices are interconnected to form a network is called network topology.

Bus Topology ■ In case of Bus topology, all devices share single communication line or cable. ■ It is one of the simple forms of networking where a failure of a device does not affect the other devices. ■ But failure of the shared communication line can make all other devices stop functioning.

Star Topology ■ All hosts in Star topology are connected to a central device, known as hub device, using a point-to- point connection. ■ That is, there exists a point to point connection between hosts and hub..

Ring Topology ■ In ring topology, each host machine connects to exactly two other machines, creating a circular network structure.

Mesh Topology ■ In this type of topology, a host is connected to one or multiple hosts.This topology has hosts in point-to-point connection with every other host or may also have hosts which are in point-to-point connection to few hosts only.

Tree Topology ■ Tree topology has a group of star networks connected to a linear bus backbone cable. It incorporates features of both star and bus topologies. Tree topology is also called hierarchical topology.