Pin is also somewhat dangerous tactic. Just because you think the piece is pinned, doesn't make it so. Well when a piece or pawn is pinned to a king, then it's pinned for good, but other than that, better watch out.
The pin

For more about the basics of pins, please check out this new blog post:
http://chesstrainerapp.blogspot.fr/2014/01/the-pin.html
The pin is a powerful move. Let`s say the Bishop is "pinning" the pawn to the king. The pawn cannot move or the king will be in check.
Use the pin, chess players, and who knows -- you just might get more points!