It is a rope fitted around the rim of a fixed wheel. Some pulleys increase the force that is applied to them .Other change the direction of the force.They are used to raise and lower things such as...
why you use a simple machine is it make work easier. then if you did it own your own. that's not an answer
Hmm, for me, it would probably be my bicycle.
Simple machines are much easier to make than complex machines.
Wheel and axle, and levers.