The series has spawned a few spinoffs that air between main seasons, all of which use an accelerated schedule (a single round of auditions and a finale) and an audience of 'superfans' instead of nationwide live voting. One of the main features of the show is the panel of judges who can each hit a buzzer during acts they hate, and if all judges buzz an act then it ends then and there. People audition to win $1,000,000 and, since Season 3, a contract to perform in Las Vegas (usually via a tour featuring them and other high-ranking participants from the season). It was launched in 2006 and is still ongoing.
America's Got Talent is a Talent Show created by Simon Cowell which takes the American Idol concept and expands it to pretty much anything you think people will pay to see - or not, in the case of the bad acts.