What is difference between Linux and Unix

Unix is just command based but linux have graphical version . Linux iis also the clone of the unix .

I think you are right rohit and this link is confirm your answer

http://www.cyberciti.biz/faq/what-is-the-difference-between-linux-and-unix/

Linux was developed from Mimix,another version of unix.Earlier,UNIX was paid version before linux was developed.Above link explain linux and unix very nicely.