Here are some shells:
Bourne (sh): this is the
original Unix shell, available in nearly every flavor of Unix.
Korn (ksh): a
backwards-compatible upgrade to the Bourne shell, developed by
David G. Korn at AT&T Bell Laboratories.
Bash (bash): Bourne-again shell, a public domain shell
containing features of the Bourne, Korn and c-shell.
(csh) and T-C-Shell (tcsh): The c-shell is similar to C programming
language; t-c-shell extends csh.
Z-Shell (zsh): an open-source Unix shell.
You can see what shells are available on your system like this:
$ cat /etc/shells
You can see what shell you are currently using like this:
$ echo $SHELL