A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or fulcrum. A lever is a rigid body capable of rotating on a point on itself. On the basis of the location of fulcrum, load and effort, it is one of the earliest machines identified by Renaissance scientists.

A lever amplifies an input force to provide a greater output force, which is said to provide leverage. The ratio of the output force to the input force is the mechanical advantage of the lever. The word "lever" entered English about 1300 from Old French, in which the word was 'levier'. This sprang from the stem of the verb lever, meaning "to raise".

The earliest evidence of the lever mechanism dates back to the ancient Near East circa 5000 BC, when it was first used in a simple balance scale. In ancient Egypt circa 4400 BC, a foot pedal was used for the earliest horizontal frame loom. In ancient Egypt technology, workmen used the lever to move and uplift obelisks weighing more than 100 tons. This is evident from the recesses in the large blocks and the handling bosses which could not be used for any purpose other than for levers.

The earliest remaining writings regarding levers date from the 3rd century BCE and were provided by Archimedes. He stated, 'Give me a lever long enough and a fulcrum on which to place it, and I shall move the world.'

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