What is a compound bow
A compound bow is a modern day bow that uses a levering system, usually of cables and pulleys, to bend the limbs.
The limbs of a compound bow are usually much stiffer than those of a recurve bow or longbow. This limb stiffness makes the compound bow more energy efficient than other bows, but the limbs are too stiff to be drawn comfortably with a string attached directly to them. The compound bow has the string attached to the pulleys, one or both of which has one or more cables attached to the opposite limb. When the string is drawn back, the string causes the pulleys to turn. This causes the pulleys to pull the cables, which in turn causes the limbs to bend and thus store energy.
The use of this levering system gives the compound bow a characteristic draw-force curve which rises to a peak weight and then lets off to a lower holding weight.