Lever, simple machine consisting of a rigid bar that rotates about a fixed point, called a fulcrum. Levers affect the effort, or force, needed to do a certain amount of work, and are used to lift heavy objects.
The lever is one of the simplest, but most useful, machines there are. A lever consists of a beam or rod that is fixed to a point, allowing it to rotate on itself. The lever is useful because it amplifies the force that is put on it (provides "leverage"). The lever is used in modern society in many different ways. For example, it is often used in construction in order to lift weights.
