A celebrity is typically someone who is famous for being famous, having no other obvious talent or ability than possibly being good-looking, or having done something worthwhile or creative some time in the distant past. British examples that spring to mind are
David Frost,
Bob Geldof,
Tara Palmer-Tomkinson, but every country has its fair share.
More fortunate celebrities may get their own column in a newspaper or magazine, or a TV show interviewing other celebrities. But there are far too many celebs for them all to have their own show, and for this reason TV and radio producers invented the panel game.
Martin Amis has suggested that the correct spelling of this word is a-s-s-h-o-l-e.