The BIG Bang Theory is a popular American sitcom that aired from 2007 to 2019. It follows the lives of four socially awkward friends, Leonard, Sheldon, Howard, and Raj, as they navigate their careers and relationships. The show is based on the scientific theory of the same name, which states that the universe began with a massive explosion of energy and matter. The show was a huge success, winning numerous awards and becoming one of the most watched shows in television history.