A disc jockey, more commonly abbreviated as DJ, is a person who plays recorded music for an audience. Types of DJs include radio DJs, club DJs, mobile DJs, and turntablists. Originally, the "disc" in "disc jockey" referred to shellac and later vinyl records, but nowadays DJ is used as an all-encompassing term to also describe persons who mix music from other recording media such as cassettes, CDs or digital audio files on a CDJ, controller, or even a laptop. DJs may adopt the title "DJ" in front of their real names, adopted pseudonyms, or stage names.

A radio personality is a person who has an on-air position in radio broadcasting. A radio personality who hosts a radio show is also known as a radio host, radio presenter or radio jockey. Radio personalities who introduce and play individual selections of recorded music are known as disc jockeys or "DJs" for short. Broadcast radio personalities may include talk radio hosts, AM/FM radio show hosts, and satellite radio program hosts, and non-host contributors to radio programs, such as reporters or correspondents.