The computer's master control program. When a computer is turned on, a small "boot program" loads the operating system. Although additional system modules may be loaded as needed, the main part, known ...

Microsoft Windows Server OS (operating system) is a series of enterprise-class server operating systems designed to share services with multiple users and provide extensive administrative control of ...

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.