Builtin

A builtin (or builtin command, or shell builtin) is a command or function that is part of the shell itself. The command is "built-in" to the shell program — no external program is necessary to run the command, and a new process does not need to be created.

Builtin commands are available in most shells, including:

• The Windows command prompt
• Windows PowerShell
• Bash, the default shell of the Windows Subsystem for Linux and most Linux operating systems.

In the Windows command prompt, builtin commands are called internal commands. In PowerShell, they are called cmdlets.

Tip: In bash, and in the Windows command prompt, you can display a list of builtin commands with the command help.

Command prompt, Operating System terms