Weak square basics.
What is a wea square? A weak square is a sqaure that can't be attack by a pawn. This is also known as a hole. Lets see a example.
as we can see there a lots of holes here. The white pawns all sit on white squares and the dark squares in front of them are weak. They are hard for white to atack and black can stick his pieces on them. The best way to use a weak square is to stick a piece on it. Knights love weak squares because they can get a safe outpost in enemy territory. They are very strong when they are on these outposts. Notice how the black knight attacks 2 white pawns well white knight is forced to babysit. The black knight is superior thanks to the outpost he is on.