application software such as a word processor, which enables a user to perform a task, and system software such as an operating system, which enables other software to run properly, by interfacing with hardware and with other software.
System software helps run the computer hardware and computer system. It includes operating systems, device drivers, diagnostic tools, servers, windowing systems, utilities and more. The purpose of systems software is to insulate the applications programmer as much as possible from the details of the particular computer complex being use, especially memory and other hardware features, and such accessory devices as communications, printers, readers, displays, keyboards, etc.
Application software allows humans to accomplish one or more specific (non-computer related) tasks. Typical applications include industrial automation, business software, educational software, medical software, databases and computer games. Businesses are probably the biggest users of application software, but almost every field of human activity (from a-bombs to zymurgy) now uses some form of application software. It is used to automate all sorts of functions.