An artiste is a professional performer — a singer, dancer, actor, magician, or circus person — who appears in a show. English borrowed the word from French, and it still sounds a little French and theatrical. We use it for people on a stage or in variety, cabaret, or a touring show, not usually for a painter. Artist is the everyday English word; artiste is narrower and a bit old-fashioned or show-business. Sometimes it is used with a slight smile, as if the person is putting on airs. In serious talk about painting or music, say artist.