|(operating system)||command interpreter - A program which reads textual commands from
the user or from a file and executes them. Some commands may
be executed directly within the interpreter itself
(e.g. setting variables or control constructs), others may
cause it to load and execute other files.|
Unix's command interpreters are known as shells.
When an IBM PC is booted BIOS loads and runs the MS-DOS command interpreter into memory from file COMMAND.COM found on a floppy disk or hard disk drive. The commands that COMMAND.COM recognizes (e.g. COPY, DIR, PRN) are called internal commands, in contrast to external commands which are executable files.