MS-DOS Command :: help
Open a Microsoft MS-DOS command prompt shell window and type help and you will see a list of available commands with a brief description of each command.
To display detailed help information about command command, you can type either of the following help commands:
For example, help dir and dir /? displays help information about the dir command.
Displays help for the specified command command. You can either use the help command or use the /? flag following the command command.
Some commands use -help or -? as the help option. So if /? does not work, try -help instead.
Provides help information for Windows XP commands. HELP [command] command - displays help information on that command.
(Enlarge: help help)