A system software component that is external to the operating system kernel. If the phrase is used to refer to the operating system itself, it is redundant because an operating system "is" software.

Expertise from Forbes Councils members, operated under license. Opinions expressed are those of the author. A traditional operating system (OS) such as Windows, macOS and Linux facilitates user ...

A priority assigned by the operating system to programs running in a multitasking environment, which is a common mode of operation. The foreground contains the applications the user is working on, and ...