Computer Software
Software is the instructions that tell a computer how to carry out a task are referred to as a computer program. These programs form the software that prepares a computer to do a specific task such as document production, photo editing, virus protection, file management, or Web browsing.
How is software categorized?
The two main categories are system software & application software.
System software
Designed for computer-centric task for example you would use system software to diagnose a problem with your hard disk drive or Internet connection,
Application software
Designed to help people to accomplish real-world tasks. For example you would use application software to edit a photo or write a term paper.