The Big Bang Theory is an American television sitcom created by Chuck Lorre and Bill Prady, both of whom served as executive producers on the series, along with Steven Molaro. All three also served as head writers. The show premiered on CBS on September 24, 2007, and concluded on May 16, 2019, having broadcast a total of 279 episodes over twelve seasons.The show originally centered on five characters living in Pasadena, California: Leonard Hofstadter and Sheldon Cooper, both physicists at Caltech, who share an apartment; Penny, a waitress and aspiring actress who lives across the hall; and Leonard and Sheldon's similarly geeky and socially awkward friends and co-workers, aerospace engineer Howard Wolowitz and astrophysicist Raj Koothrappali. Over time, supporting characters were promoted to starring roles, including neuroscientist Amy Farrah Fowler, microbiologist Bernadette Rostenkowski, experimental physicist Leslie Winkle, and comic book store owner Stuart Bloom.
The show was filmed in front of a live audience and was produced by Warner Bros. Television and Chuck Lorre Productions. The Big Bang Theory received mixed reviews from critics throughout its first season, but reception was more favorable in the second and third seasons. Despite early mixed reviews, seven seasons of the show have ranked within the top ten of the final television season ratings, ultimately reaching the no.