Types of software:

A layer structure is described where Operating System is located on generally used software systems on desktops

System software

System software used to run the computer system and computer hardware. It includes a combination of the following:

• Device drivers
• Operating systems
• Servers
• Utilities
• Windowing systems

The reason behind the systems software is to unburden the applications programmer from the frequently complex details of the specific computer being used, with such accessories as communications devices, device readers, printers, keyboards and displays, and also to partition the computer's resources such as processor time and memory in a safe and stable manner. For Examples: Windows XP, Linux and Mac.

Programming software

Programming software generally provides tools to assist a programmer in writing computer programs, and developing software by using different programming languages in a more convenient way. The tools include are following:

• Compiler
• Debuggers
• Interpreters
• Text editors
• Linkers
• Application software

Application software permits end users to accomplish one or more particular (not directly computer development related) tasks. Typical applications include following:

• Industrial automation
• Business software
• solid state physics software and Quantum chemistry
• Computer games
• Databases
• Telecommunications (i.e., the internet and everything that flows on it)
• Medical software
• Educational software
• Molecular modeling software
• Military software       
• Spreadsheet
• Image editing
• Simulation software
• Decision making software
• Word processing