Shell Types

• The Bourne (or standard) shell, the most compact shell but also the simplest.
• The Korn shell, a superset of the Bourne shell that lets you edit the command line.
• The C shell, which uses C syntax and has many conveniences.

Most systems have more than one shell,

The /etc/passwd file determines which shell takes
If the program Your shell will be the:

shell name is: 
/bin/sh Bourne shell
/bin/rsh Restricted Bourne shell
/bin/jsh Bourne shell, including job control
/bin/ksh Korn shell
/bin/rksh Restricted Korn shell
/bin/csh C shell

change from the Bourne shell to the C shell, type:     $ exec csh