Exactly How can we define "sh ksh csh &bash"

Hi -
I m prashant. I m new in UNIX&LINUX world. I want to ask that how can we define the shell in Linux like bash,ksh,csh in Linux. What is the use of these shells. I know there are mny experts on net if you can tell me then please do me this favour and tell me about this topic.

Prashant singh,

Thanks in advance

The question that you have asked requires a detailed explaination, something that is difficult to provide on a forum. May be you could check out some sites that offer tutorials on using and programming the shell. Check this site for an introduction to the bash shell, this is an introduction to ksh.