There are three general software classifications:

	Operating or System Software (MS DOS, Windows 9.x, 2000, XP)
	Application Software (MS Office: (Word) Word-processing; (Excel) spreadsheets, (Access) databases; (Publisher) desktop publishing;  (PowerPoint) Multimedia.
	Programming Software: (allow users to create software applications for his or her own use). Examples are: Visual Basics, C++

System software helps the computer carry out its basic operating tasks. This category of software contains programs that perform tasks essential to the efficient functioning of computer hardware. I.e.: Operating Systems: MS-DOS; Windows; Unix; OS/2:
An operating system works like an air traffic controller at LA-X to coordinate the activities within the computer. Just as a planes would crash at an airport because they cannot properly function without air traffic controllers, a computer cannot function without an operating system. It provides a variety of services that you can use to run programs and manage your data.

Application software helps the human user carry out a task. It helps you produce documents, perform calculations, manage financial resources, create graphics, etc. I.e.: MS Word; Excel; PowerPoint; Access.

The operating system provides various services:

	Control Basic Input Output: controls data flow into an out of the computer. I.e. it routes output to a printer
	Detect Equipment failure: monitors the status of critical computer components to detect failures that affect processing
	Allocates System Resources so programs run properly. I.e.: it ensures enough available space for each program that is running
	Manages store space: It keeps track of the data stored on disks and CD-ROMS
	Security maintenance: I.e. it might not allow you to access the computer without password or ID.