A turbine is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and water wheels.

Gas, steam, and water turbines usually have a casing around the blades that contains and controls the working fluid. Credit for invention of the steam turbine is given both to the British engineer Sir Charles Parsons (1854–1931), for invention of the reaction turbine and to Swedish engineer Gustaf de Laval (1845–1913), for invention of the impulse turbine. Modern steam turbines frequently employ both reaction and impulse in the same unit, typically varying the degree of reaction and impulse from the blade root to its periphery.

The word "turbine" was coined in 1822 by the French mining engineer Claude Burdin from the Latin turbo, or vortex, in a memoir, "Des turbines hydrauliques ou machines rotatoires à grande vitesse", which he submitted to the Académie royale des sciences in Paris.Benoit Fourneyron, a former student of Claude Burdin, built the first practical water turbine.

James Douglas Muir "Jay" Leno /ˈlɛnoʊ/ (born April 28, 1950) is an American stand-up comedian and television host.

From 1992 to 2009, Leno was the host of NBC's The Tonight Show with Jay Leno. Beginning in September 2009, Leno started a primetime talk show, titled The Jay Leno Show, which aired weeknights at 10:00 p.m. (Eastern Time, UTC-5), also on NBC. After The Jay Leno Show was canceled in January 2010 amid a host controversy, Leno returned to host The Tonight Show with Jay Leno on March 1, 2010.

James "Jay" Leno was born in New Rochelle, New York, in 1950. His mother, Catherine (née Muir; 1911–1993), a homemaker, was born in Greenock, Scotland, and came to the United States at age 11. Leno's father, Angelo (1910–1994), who worked as an insurance salesman, was born in New York to immigrants from Flumeri, Italy. Leno grew up in Andover, Massachusetts, and although his high school guidance counselor recommended that he drop out of school, he later obtained a Bachelor's degree in speech therapy from Emerson College, where he started a comedy club in 1973. Leno's siblings include his late older brother, Patrick, who was a Vietnam veteran and a lawyer.