Which is better, the bird pulley or the crown block?

Bird-moving pulley refers to a pulley system in which the pulley can rotate freely. Its advantage is that it can reduce the friction caused by the change of force direction and make it easier to apply force. Bird pulley is suitable for scenes that need to change the direction of force, such as lifting heavy objects or changing the direction of motion of objects.

Crown block refers to the pulley system in which the pulley is fixed in one position and cannot rotate freely. Its advantage is that it can increase strength and make it stronger. The crown block is suitable for scenes that need to be reinforced, such as lifting heavy objects or improving the moving speed of objects.