Computer Software

Software, also called a program, consists of a series of related instructions, organized for a common purpose, that tells the computer what tasks to perform and how to perform them.

 You interact with a program through its user interface. The user interface controls how you enter data and instructions and how information is displayed on the screen. Software today often has a graphical user interface (GUI), you interact with the software using text, graphics, and visual images such as icons. An icon is a miniature image that represents a program, an instruction, or some other object. You can use the mouse to select icons that perform operations such as starting a program.

 The two categories of software are system software and application software.

System Software

 System software consists of the programs that control or maintain the operations of the computer and its devices. System software serves as the interface between the user, the application software, and the computer's hardware. Two types of system software are the operating system and utility programs.

Operating System An operating system is a set of programs that coordinates all the activities among computer hardware devices. It provides a means for users to communicate with the computer and other software. Many of today's computers use Microsoft's Windows, or Mac OS, Apple's operating system.

 When a user starts a computer, portions of the operating system are copied into memory from the computer's hard disk. These parts of the operating system remain in memory while the computer is on.

Utility Program A utility program allows a user to perform maintenance-type tasks usually related to managing a computer, its devices, or its programs. For example, you can use a utility program to transfer digital photos to an optical disc. Most operating systems include several utility programs for managing disk drives, printers, and other devices and media. You also can buy utility programs that allow you to perform additional computer management functions.

Application Software

 Application software consists of programs designed to make users more productive and/or assist them with personal tasks. A widely used type of application software related to communications is a Web browser, which allows users with an Internet connection to access and view Web pages or access programs. Other popular application software includes word processing software, spreadsheet software, database software, and presentation software.

 Many other types of application software exist that enable users to perform a variety of tasks. These include personal information management, note taking, project management, accounting, document management, computer-aided design, desktop publishing, paint/image editing, photo editing,audio and video editing, multimedia authoring, Web page authoring, personal finance, legal, tax preparation, home design/landscaping, travel and mapping, education, reference, and entertainment (e.g., games or simulations, etc.).

 Software is available at stores that sell computer products and also online at many Web sites.

Installing and Running Programs

 When purchasing software from a retailer, you typically receive a box that includes an optical disc(s) that contains the program. If you acquire software from a Web site on the Internet, you may be able to download the program; that is, the program transfers from the Web site to the hard disk in your computer.

 The instructions in software are placed on storage media, either locally or online. To use software that is stored locally, such as on a hard disk or optical disc, you usually need to install the software. Web applications that are stored online, by contrast, usually do not need to be installed.

 Installing is the process of setting up software to work with the computer, printer, and other hardware. When you buy a computer, it usually has some software preinstalled on its hard disk. This enables you to use the computer the first time you turn it on. To begin installing additional software from an optical disc, insert the program disc in an optical disc drive and follow the instructions to begin installation. To install downloaded software, the Web site typically provides instructions for how to install the program on your hard disk.

 Once installed, you can run the program. When you instruct the computer to run an installed program, the computer loads it, which means the program is copied from storage to memory. Once in memory, the computer can carry out, or execute, the instructions in the program so that you can use the program.

Software Development

 A programmer, sometimes called a computer programmer or developer, is someone who develops software or writes the instructions that direct computer to process data into information. When writing instructions, a programmer must be sure the program works properly so that the computer generates the desired results. Complex programs can require thousands to millions of instructions.

 Programmers use a programming language or program development tool to create computer programs. Popular programming languages include C++, Java, JavaScript, Visual C#, and Visual Basic.