Todd Carty is an actor, fairly well-known over here because he is in a popular soap called
EastEnders.
http://en.wikipedia.org/wiki/Todd_CartyThe format is that a professional dancer is asked to team up with a celebrity, and they form a dance partnership that rehearses and dances on TV week on week.
Each performance is judged by a panel of judges and then by the viewing audience who can phone up to vote.
The two couples that get the lowest overall score at the end have to face an elimination process called the skate-off, and the judges decide who they want to keep.
Thus one couple is voted out each week, until there are only two left. They battle it out for the year's title in the final.
Very often, the public vote will keep a couple in who are not very good (they don't make the elimination round, so the judges cannot get rid of them) because they like the entertainment that it provides to see them mess up time and again. Poor celeb dancers therefore end up knocking really good ones out, sometimes reaching the quarter-final.
I believe other countries have
Dancing with the Stars which is our
Strictly Come Dancing in its exported form. Viewers of that programme will be familiar with the format.