Simon Cowell's 'X Factor' Vs. 'American Idol': What's The Difference?

While they're both reality competitions, key differences separate the shows.

Now that Simon Cowell has announced that he will vacate his "American Idol" judge's chair after nine seasons to settle in for a U.S. version of "The X Factor," the question for many fans was: What is "The X Factor"?

Currently shown in 17 countries across the world — from Australia to Morocco to Spain — "X Factor" is a reality competition that Cowell created and appears on as a judge. While it incorporates elements of "Idol," it also differs in several key areas. Similarities between "Factor" and "Pop Idol" (the progenitor of "American Idol") actually became the focus of a lawsuit between "Idol" creators Simon Fuller and Cowell. In the settlement, Fuller and his 19 Entertainment received a minority stake in "Factor."

The British version of the show begins with an audition round, where contestants perform in front of judges and a live audience. As on "Idol," there are actually several sets of auditions that singers must pass to secure a shot to perform in front of the judges; only the judges' audition is aired. Singers that make the cut are then sent on to a so-called "boot camp" round. Unlike "Idol," "Factor" allows groups as well as solo artists to compete. Though the categories have changed over the show's six seasons, current groups also include boys, girls and over-25s. Following another elimination during boot camp, the remaining singers are then assigned a judge who mentors them. Finally, 12 singers are sent through to the final round: live televised performances that have viewers vote for their favorites.

The British show's most notable winner is Leona Lewis, who triumphed during the third season. On the most recent season, Danyl Johnson's performance of "With a Little Help From My Friends" became a viral hit, though 18-year-old Joe McElderry eventually won the crown. Along with Cowell, the show's judges include Dannii Minogue and Cheryl Cole.

The U.S. version will launch in fall 2011, with Cowell acting as both executive producer and judge. Bringing "X Factor" to American soil had long been Cowell's wish, and back in September, reports indicated he was negotiating with Fox for a deal that could ultimately pay him $50 million a season if "Factor" becomes a hit.

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