A lever is a simple machine consisting of a beam or rigid rod pivoted at the fulcrum (fixed hinge). From the location of fulcrum, load, and effort, the lever is categorized into three classes i.e.
Class 1: Fulcrum in the middle
Class 2: Resistance (or load) in the middle
Class 3: Effort in the middle
Archimedes proves the principle of lever and Fulcrum. It states that "if the distance from the fulcrum to the point of input force is greater than the distance from the point of output, then liver amplifies the force" and vice-versa.