A "celebrity" means anyone who is "celebrated," although that meaning of "celebrated" is old-fashioned and not used much. "Celebrated" literally means "honored," but it usually means "celebrated far and wide." That is to say, "celebrated" is a synonym for "famous." There's no precise distinction, but "celebrity" suggests a less elevated status; temporarily famous, famous in magazines rather than history books, famous in pop culture. Christina Kirchner is "famous," Miley Cyrus is merely "a celebrity." If someone is on a magazine cover, but we don't know his or her name, then they are not "a celebrity."

Good question! We are always talking about famous people, whether actors, sports figures, designers, or whoever is very well known to the public for entertainment/fashion. This doesn't include politicians. Beautiful people who appear in magazines are models. Models also do fashion shows and print ads. They are basically people who are paid to be pretty.