A lever ( /ˈlɛvər/ or UK /ˈliːvər/) is constructed from a beam attached to ground by a hinge, or fulcrum. It is one of the six simple machines identified by Renaissance scientists. The word comes from the French lever, "to raise", cf. a levant. 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 ideal mechanical advantage of the lever.

The earliest remaining writings regarding levers date from the 3rd century BC and were provided by Archimedes. "Give me a place to stand, and I shall move the Earth with a lever" is a remark of Archimedes who formally stated the correct mathematical principle of levers (quoted by Pappus of Alexandria).

It is assumed that in ancient Egypt, constructors used the lever to move and uplift obelisks weighting more than 100 tons.

A lever is a beam connected to ground by a hinge, or pivot, called a fulcrum. The ideal lever does not dissipate or store energy, which means there is no friction in the hinge or bending in the beam. In this case, the power into the lever equals the power out, and the ratio of output to input force is given by the ratio of the distances from the fulcrum to the points of application of these forces. This is known as the law of the lever.

A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that provide mechanical advantage (also called leverage).

Usually the term refers to the six classical simple machines which were defined by Renaissance scientists:

A simple machine is an elementary device that has a specific movement (often called a mechanism), which can be combined with other devices and movements to form a machine. Thus simple machines are considered to be the "building blocks" of more complicated machines. This analytical view of machines as decomposable into simple machines first arose in the Renaissance as a neoclassical amplification of ancient Greek texts on technology, and is still a central part of engineering in today's age of applied science. For example, wheels, levers, and pulleys are all used in the mechanism of a bicycle. Between the simple machines and complex assemblies, several intermediate classes can be defined, which may be termed "compound machines" or "machine elements". The mechanical advantage of a compound machine is simply the product of the mechanical advantages of the simple machines of which it is composed.

Sutton Lenore Foster (born March 18, 1975) is an American actress, singer, and dancer. Foster has received two Tony Awards, in 2002 for her role of Millie Dillmount in Thoroughly Modern Millie and in 2011 for her role of Reno Sweeney in Anything Goes. Her other Broadway credits include Little Women, The Drowsy Chaperone, Young Frankenstein and Shrek the Musical. She also is starring in the upcoming television series Bunheads.

Foster was born in Statesboro, Georgia and raised in Troy, Michigan. At age fifteen, she was a contestant on the television show Star Search and also auditioned for the cast of The Mickey Mouse Club. She left Troy High School before graduating (she received her diploma via correspondence courses) to join the national tour of The Will Rogers Follies directed by Tommy Tune. She then attended Carnegie Mellon University for one year, but left to pursue a theatrical career full-time. May 2012, she received an honorary doctorate from Ball State University. Her brother is actor Hunter Foster.

John Prakasa Rao Janumala, famously known as Johnny Lever born January 7, 1950 in Ossalapalle, Prakasam District, Andhra Pradesh, is an Indian film actor and one of the most popular comedians in Hindi cinema. He was born to Prakash Rao Janumala and Karunamma Janumala and brought up in Mumbai. He began his career in 1984, and has acted in more than 300 Bollywood films since. He has received 13 Filmfare Awards nominations in Best Comedian Category, and has won the award twice.

Johnny Lever, born in Andhra Pradesh and was brought up in Mumbai's King's Circle area (Dharavi). His mother tongue is Telugu. Johnny studied in Andhra Telugu School till the seventh grade but couldn't study further because of financial problems in his family, after which he decided to leave school and started working different kinds of odd jobs, such as selling pens on the streets of Bombay by imitating Bollywood stars and dancing to the songs of Bollywood stars. He also spent his early ages in Yakutpura a old city of Hyderabad from where he learnt the unique style of comedy acting. He developed a passion for mimicry and stand-up comedy, inspired by watching comedians like Johnny Walker, Kishore Kumar and Mehmood in films and mimicry artists like Dinesh Hingoo and Nerella Venumadhav on stage, and thus decided to be a mimicry artist. To seek guidance and help regarding mimicry, he met his mentor Pratap Jani and mimicry artist Ram Kumar, who helped him and taught him the basics of mimicry.