Let me tell you what are internal commands. To get help on each internal command, add a switch "/?" after the command when you use them. For detailed information, if you are MS-DOS 5 or higher, Windows NT or Windows 2000, you can type "help [command]" for help. Notice the following: [optional_item]; <necessary_text>; /switch; selective_itemA | selective_itemB; are usually seen in command help texts. For information about the command interpreter, click here: COMMAND.COM.
Mainly, internal commands are file and directory operation commands: