Differance between Bourne, Korn and C Shells

What is the differance between "C-Shell", "Korn-Shell" and "Bourne-Shell"? Please explain me!

Google for "shell differences and how to change your shell".

Comparison of computer shells - Wikipedia, the free encyclopedia

My 2 cents: I prefer Korn shell over Bash or csh, because I make use of the floating point arithmetic and hash tables for pattern scanning (Yes I know, awk does that). They help me deal with financial statements and give me more flexibility working with schedules and "spread sheets".

Not that bash or csh are bad. Not at all. It is just a niche for ksh that I use more often.

See Difference between ksh,bash and different shells.