A text-based interface to a computer operating system. Users type text commands into the command interpreter in order to execute various routines and manage system and networking resources.
Traditional UNIX systems make heavy use of the command interpreter, and MS-DOS, the legacy Microsoft operating system, used a command interpreter to process text-based commands to control operating system processes.
On systems based on Microsoft Windows, users can still open a command prompt to issue various text-based commands for controlling different aspects of the system, but these commands represent only a subset of the full functionality of the GUI-based administration tools available on Windows platforms.
The command interpreter is sometimes referred to as the operating system shell, especially on UNIX platforms. Entering a command into the command interpreter is referred to as «working at the command line».