What "bishop" means in chess

A bishop is a chess piece that is usually represented as a tall, narrow piece with a pointed head. In the standard chess set, each player has two bishops, one that starts on a light square and one on a dark square. The bishop can move diagonally any number of squares as long as it is not obstructed by another piece. Bishops are often considered more powerful than knights, but less powerful than rooks and the queen.