The C-shells have a few commands not available in the Bourne shell.
Good examples are the alias command and the history command.
Bourne shell is almost never used as an interactive environment, so the examples here will not deal with it. The plain C-shell is set up as your default shell as it is generally easier for novice UNIX users to learn. It is also available on every UNIX system. The version on our SunOS4 systems was obtained from a third-party software company. The TC-shell provides this facility with command names as well as file names.