1. Software Software consists of the instructions issued to the computer to perform specific tasks. –The software on a computer system refers to the programs that make the computer run.

2. Types of Software Although there are literally thousands of software programs you can buy, there are really only two types of software: application and systems. –Application software computer software created to allow the user to perform specific job or task. –Systems software computer software responsible for the general operation of a computer system, including the operation of hardware, running application software and file management.

3. Application Software Application software is also called productivity software. It allows an end user to perform some task. The most commonly used categories of application software are –Word-processing programs –Spreadsheet software –Database software –Presentation software –Desktop publishing programs –Games

4. Systems Software Systems software consists of programs that coordinate and control the resources and operations of the computer itself. The three categories of systems software are –Operating systems –Utility programs –Language translators

5. Systems Software – Operating Systems Operating systems is system software that acts as a “go-between”, allowing computer hardware and other software to communicate with each other. There are many brands and versions of operating systems. An operating system is designed to work with a specific processor chip. –For example, Windows operating systems are designed to work with an Intel processor (or clone) and will not usually work on a Macintosh computer.

6. Illustration of an Operating System This figure shows how an operating system acts as an interface between the user, the application programs, and the computer.

7. Systems Software - Utilities Utility programs are designed to help perform housekeeping chores for the computer. They can be designed to –Manage the computer’s resources. –Do file management. –Format disks. –Copy files from one disk to another. –Back up data to disk or tape.

8. Common Utility Programs Disk Formatting prepares disk to have files stored on it. File Management allows a user to perform tasks such as copying, moving, and deleting files. File Recovery attempts to recover a file that has been erased.

9. Common Utility Programs Uninstall removes an application program no longer needed. Diagnostic provides detailed information about the computer system and attempts to locate problems. File Conversion converts a file from one format to another.

10. Common Utility Programs Disk Compression frees up storage space on a disk by compressing existing files. Backup makes a duplicate copy of the contents of a secondary storage device. Antivirus protects the computer system from viruses. Disk Defragmentation attempts to place segments of each file on the hard disk as close to one another as possible.

11. Systems Software – Language Translators Computers cannot read program statements in programming language format, such as Visual Basic or Java program statements. Language translator programs convert English-like software programs into machine code that can be understood by the computer. Each converted English-like instruction may be translated into many machine code instructions. Once converted to machine code, the program can be run and executed by the computer.

12. Microcomputer Operating System Interfaces The user interface of an operating system is what we are all familiar with. The User Interface is the part of the operating system that you interact with when using your computer.

13. Microcomputer Operating System Interfaces There are two commonly used types of operating system interfaces: –Command-line interface: With this interface, you must type exact commands into the computer from a command prompt. This is not a user-friendly interface, and you must memorize many commands and keywords. –Graphical user interface: Users manipulate on-screen icons to perform functions, usually with a mouse or other pointing device.

14. User Interface Comparison The figure on the left shows a command-line interface, where commands are typed in at the prompt. The figure on the right is a graphical user interface (GUI) where users perform actions by clicking and manipulating icons.

15. The Windows Operating System Windows was Microsoft’s first GUI operating system, released in 1987. Applications installed on a Windows system appeared as icons. Multitasking is the ability to run more than one program at a time. The first true multitasking version of Windows was Windows 95. –This version also included support for networking computers.

16. Windows Versions Windows 98 improved on Windows 95 and offered Internet integration and support for the USB bus. Windows 2000 was an update to Windows 98 and Windows NT and included tools for Web site creation. We use Windows XP, which provides increased stability and device recognition over earlier Windows versions. Windows 7 is the latest version of Windows Operating System.

17. Network Operating Systems A network operating system (NOS) is designed to allow multiple computers to be connected and talk to each other. Logon the action of gaining access to a computer or a network by entering a username and password. Networks can consist of anywhere from two to many thousands of computers. While there are many network operating systems available, the most popular are –Microsoft Windows NT and Windows 2000 –Novell’s Netware –IBM’s Warp Server