We all know that chess is about checkmating your opponent.  This is easier to do when you have more pieces than him.  But how do you do that you ask well by forking your opponents king and another piece forking is when you put a king in check and are able to kill another piece you'll see an example below.

I hope that helped if you want a challenge try the puzzle below. This might have been one of my best games and shows a beautiful example of forking.

If you thought this was helpful or the puzzle was hard fell free to say so.