input force refers to the force exerted on a machine, also known as the effort, while the output force is the force machines produce or the Load. The ratio of output force to input force gives the mechanical advantage of a simple machine
The output force exerted by the rake must be less than the input force because one has to use force while raking. The force used to move the rake is the input force.
The rake is not going to be able to convert all of the input force into output force, the force the rake applies to move the leaves, because of friction.
