In the operating system MS-Dos , standard system commands have been provided. These commands are meant to carry out common tasks like deleting specific files, changing the directory, listing contents of the specified directory, etc, and in effect create a convenient user interface. The access to the list of basic commands that can be used in the Dos prompt can be really helpful from the user's point of view. In MS-Dos, there is also a help page that opens up once 'type /?' is inserted after the command and this gives additional information about the command.