There are many differences.

A difference between the csh and sh is:

   Korn (ksh)                           C (csh)
   --------------------------------------------
   
   $ echo HOME               $ echo HOME
   HOME                      HOME     
   $                         $

   $ echo $HOME              $ echo $HOME 
   /home/cps444-n1.19        /home/cps444-n1.19
   $                         $

   $ echo $home              $ echo $home
                             /home/cps444-n1.19
   $                         $


Another difference between the Korn (ksh) and C (csh) shells is:

The ... in the Korn shell is ..., while in the C shell it is ....