Operating System (OS)

-It is the most important program which runs on a computer.
-Every computer must have it in order to operate.
-Operating System controls all hardware and software, without it your computer wouldn’t make any sense.

•Hundreds of different Operating Systems
•Examples of OS are Microsoft Windows Operating System (like Windows 98, Windows 2000, Windows NT, Windows XP), MS DOS( Microsoft Disk Operating System), Linux.

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Tailor made software or User software

•User software tailors systems to meet the users specific needs.
•User software includes scientific simulations, graphics, animation scripts, etc... Even email filters are a kind of user software; users create this software themselves

Application Software

•Application software allows a user to accomplish one or more specific tasks, like office suites and video games.
•Application software is often purchased separately. Applications are what most people think of when they think of software.