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.

Komal Nahta is the editor and publisher of "Film Information", India's largest film trade journal. He is also an anchor of the Trade show ETC Bollywood Business on the Bollywood TV channels ETC and Zee Cinema. He is also the co-owner of koimoi.com which is a joint foray into the Online Entertainment & News segment in partnership with Mr. Alok Kejriwal (CEO, Games2Win India Pvt. Ltd.). He is also the Chairman of Eros International.

His interviews are carried by many satellite channels, including CNBC, STAR, Zee, B4U, NDTV, Zoom and Doordarshan. He was also the Bollywood representative of the BBC for almost 10 years. The Asian Development bank(ADB) has appointed him advisor for its film financing division, the first person from the film industry to be so appointed. He has recently launched a new tabloid called "The Film Street Journal".

On 26 April 2010, Nahta replaced Taran Adarsh as the host of ETC Bollywood Business on the indian TV channels ETC (India) and Zee Cinema (UK). The show airs daily on weekdays at 8:30 pm in India and at 7:30 pm in the UK. On Mondays, the show is about the previous fridays collections. On Tuesday and Wednesday, Nahta speaks to various artists from the film industry. Thursdays preview films releasing on Friday. On Fridays, Nahta will be review films released on that day. The show launched the first episode with Sajid Nadiadwala as the guest. He is also the Editor of Entertainment website www.koimoi.com He has also given a special appearance in the 2010 comedy, Tees Maar Khan, along with Akshay Kumar, Katrina Kaif and Akshaye Khanna.