Difference between Crysis and Crysis:Warhead?

Im wanting to buy one of these, but they are both just as cheap. I looked it up on YouTube and both the games look nearly the same! What is the difference?

Warhead is an expansion/sequel, I believe.

Quote from Wikipedia :Crysis Warhead is a stand-alone expansion that allows the player to play the story told in the original Crysis, but this time from the viewpoint of Sgt. Michael Sykes, also known as "Psycho".

Replying to #3

But is it better than the original?

tehuber1337 · #2Warhead is an expansion/sequel, I believe.

=but if its an expansion, does it mean i need to buy the first Crysis?

CRYSIS WARHEAD is a different game with different main character and it sets on the other side of the island at the same period of time.(both games take place at the same time).CRYSIS WARHEAD has faster pace,better graphics and surprisingly better optimised!
(it has better graphical options)