The Bishop is a long range piece that can be very powerful, but it has a significant weakness - it can only ever move on squares of one colour. Each player starts the game with two bishops - one that moves on light squares, and one that moves on dark squares - so between them, the two bishops can cover all the squares on the board.
The bishop can move any number of squares in a straight diagonal line, so long as the squares between the bishop and its destination are unoccupied. The diagram below shows the legal moves for a bishop.
Unlike the knight, the bishop cannot jump over obstacles, so if something is blocking its path, the bishop can go no further. On the board below, drag the white bishop to make a legal move:
The bishop captures the same way it moves. On the diagram below, make a capture with the white bishop: