Technology Applications

Understanding 0000 System Software Understanding System Soft- ware © Pearson Education, Inc.46 Chapter 4

What Is the Purpose of an Operating System? When you use a computer program, most of the activity you see on the screen is conducted by the operating sys- tem. An application, such as a word processor, asks the operating system to perform actions, such as opening a file, printing a document, or showing a list of recently used documents. To fulfill these requests, the operating system needs to know how to handle different file formats, or stan- dards used to save data on a disk. Those formats deter- mine how text documents, graphics, audio, and video files are stored and used. The operating system also maintains the settings that allow all hardware in the computer to be used. System utilities help make sure that the operating system and the computer run smoothly as they perform their tasks. Chapter Outline© Pearson Education, Inc. Lesson 4–1 What’s Online Exploring the Operating Interactive tutorials System Vocabulary Preview worksheet Lesson 4–2 Exploring System Learn More interactivities Utilities Check Your Understanding instant feedback assessment Check Your Knowledge instant feedback assessment Interdisciplinary practice activities Interdisciplinary application activities Understanding System Software 47

Lesson 4–1 Exploring the Operating SystemObjectives As You Read In Lesson 4–1 online, you will find more features and informa-• Summarize the boot Organize Information Use a tion for this lesson, including: process. concept web to help you collect information about operating • Interactive tutorials• Describe the features of a systems as you read. • As You Read worksheet graphical user interface. • Learn More interactivities • Check Your Understanding• Explain how operating systems can be configured interactive assessments and changed. • Interactive lesson review Key Terms Loading the Operating System © Pearson Education, Inc.• file format (p. 47)• boot (p. 48) The operating system, or OS, controls the computer and man-• power-on self test ages its work. The OS also provides an interface which enables you to interact with the computer. (POST) (p. 48)• window (p. 49) The Boot Process When you turn the computer on, you boot• pulldown menu (p. 49) it. That is, you start the computer, and it responds by loading the• Ribbon (p. 49) operating system. If your computer is set to show it, the first• pop-up menu (p. 49) thing you see is the BIOS screen. BIOS stands for basic input/• screen saver (p. 50) output system, and it manages and configures the computer’s hardware. This means that the computer will be able to accept48 Chapter 4 input from the keyboard and display information. The Power-On Self Test As a computer boots, it performs a series of tests called the power-on self test, or POST. During POST, the BIOS checks the major components of the system, such as its memory, keyboard, and hard drive. If your BIOS screen is set to display during POST, you will see text messages telling you what is happening. If there is a problem, a written message or a sound alerts you. If this hap- pens, the computer may need repair. If no problem is detected, parts of the operating system are loaded from storage into mem- ory and take control of the computer. The Login As the operating system starts, you may see a screen that asks you for a username and password. This is called the login screen. Businesses and schools often use this process to control who has access to the computer. Exploring the GUI When the operating system is loaded into RAM, it displays the desktop provided by the graphical user interface, or GUI. The

desktop is where all work is done, including opening and clos- Did You Know? ing programs, modifying system settings, and managing files. Icons on the desktop allow you to launch programs by clicking Today, a number of operating sys- or double-clicking them. You also can click Start (on a PC) or tems use voice recognition, which Finder (on a Macintosh®) and then the name of the program you allows you to say, for example, want. A taskbar on the desktop identifies which programs or “Computer, start word process- files are open. To switch back and forth among applications, just ing,” or “Computer, check e-mail,” click what you want to work on next. and the computer will know what you mean. However, you must Using Windows The operating system in today’s PCs and know the right commands. If you Macintosh computers displays documents in windows, or rec- say, “Ditch that file,” instead of tangular, on-screen frames that can be opened, closed, resized, “Delete that file,” the computer and rearranged to view programs or documents. Each window will not know how to process the provides commands and options. Some programs have pull- command. down menus that list commands when you select an item from the menu. Sometimes menus have submenus with additional Figure 4.1.1 The arrow in the commands. In Microsoft Office 2007, the window provides com- Number group on the Home tab mands on the Ribbon, a series of tabs at the top of the window. in Microsoft Excel 2007 displays Each tab has a group of related commands for specific tasks. A a dialog box for specifying num- command may display a dialog box that lets you set several ber formats. options at the same time. Pop-up menus, or lists of shortcut commands that appear when an area of the screen is clicked or right-clicked or the mouse button is held down, can appear anywhere in a window. Pop-up menus can be context-sensitive, providing options that relate to tasks you are doing at that moment.© Pearson Education, Inc. Understanding System Software 49