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 as the "kernel" resides in memory ...

An operating system is a collection (or suite) of programs that manages and controls the computer. Operating systems have many functions: A user interface is a program, or suite of programs that ...

The operating system is essentially a graphical front-end for MS-DOS. Indeed, Windows 1.01 ran as an MS-DOS program. Windows ...

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.