Pulleys and compound pulley systems

In a system of pulley, the equilibrium between the forces depends on the path that the rope follows.

Pulleys

 A pulley is a wheel that rotates around an axis and has a groove. We can divide pulleys into two basic types:

Compound pulley systems

Is a combination of fixed and movable pulleys. It ia also called a block and tackle system. We can combine the pulleys in various ways: