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, and people will often use the Bourne shell for writing shell scripts and will use another shell for interactive use.
The /etc/passwd file determines which shell takes effect during your interactive UNIX session. When you log in, the system checks your entry in /etc/passwd. The last field of each entry calls a program to run as the default shell. For example:
|If the program||Your shell will be the:|
|/bin/rsh||Restricted Bourne shell|
|/bin/jsh||Bourne shell, including job control|
|/bin/rksh||Restricted Korn shell|
You can change to another shell by typing the program name at the command line. For example, to change from the Bourne shell to the C shell, type: