In computing, help is a command in various command line shells such as COMMAND.COM, cmd.exe, Bash, 4DOS/4NT, Windows PowerShell, Singularity shell, Python and GNU Octave. It provides online information about available commands and the shell environment. The command is also available in the DEC RT-11 operating system.On Unix, the command is part of the Source Code Control System and prints help information for the SCCS commands.