Hello, i am new to unix.
I have a new dedicated server, and i am using SSH to shell to it.
it seems i have the option in my plesk control to give certain levels of shell access to a user. Can you please tell me what the following mean:

/bin/sh
/bin/bash
/sbin/nologin
/bin/ash
/bin/bsh
/bin/ksh
/usr/bin/ksh
/usr/bin/pdksh
/bin/tcsh/
/bin/csh
/bin/bash (chrooted)
/bin/rbash

thank you all in advance