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.

The Operating System is a base infrastructure software component of a computerized system. It controls all basic operations of the computer (or other electronic devices such as PDA, smartphone, etc.).

An operating system is a master control program that runs the computer system. In all environments, except for specialized scientific and process control applications, the operating system (OS) ...

Forbes contributors publish independent expert analyses and insights. I track enterprise software application development & data management. Your computer has an operating system, or OS. You may be ...