What is pulley explain it .it types with one example.

Dear student, A pulley is a circular disc having a groove in its edge and capable of rotating about an axle passing through its axis.A pulley is a simple machine used to change the direction of force applied . It has a groove to hold the rope. There are three basic types of pulley systems: (1) fixed, with a fixed axle, (2) movable, with a free axle, and (3) compound, with a combination of fixed and movable axles. Example- A block and tackle system, which is a basic pulley system, can illustrate how pulleys provides this kind of lifting advantage. Consider this: you have a 10-pound weight with a rope attached to it. To lift it up, you’ll need to exert 10 pounds of force straight up. If you have it attached to one pulley, you’ll still need to exert 10 pounds of force, but the direction you’ll exert is down, instead of up, thus making use of your body weight more efficiently. If you have it attached to two pulleys, you’ll need to exert only 5 pounds of force. Four pulleys, 2.5 pounds of force, and so on. Regards