This is David Sullivan for Chess NYC with the queen. The queen is the most powerful piece in chess, but she's not the most important. The queen combines the powers, of the rook and the bishop. A queen can move up, down and sideways just like a rook, but she can also move along the diagonals like a bishop. So, if you get your queen in a typically good position, which is in the center of the board, the queen radiates power out, in all directions, and can control a lot of space at once.
Here to illustrate the power of the queen, what she can and cannot do. Here we have a white queen in the middle of the board and we have some black pieces around her. In this position the queen can move in a straight line, she could capture the rook, or she could capture the queen, or she could capture this bishop. If she captured the bishop, then we see the rook could capture the queen back.
However from our staring position, the queen is not able to capture this rook on c2, notice the queen is not in a straight line to the rook so the queen cannot get this rook. And the queen is not in a straight line along the diagonal towards this bishop, so the queen cannot capture this bishop either. And that's how we use the queen.