A disc jockey (abbreviated D.J. or DJ, sometimes spelld "deejay") is a person who composes and performs music for a live audience, created from samples and loops of commercial recordings augmented with electronic instruments. (The original meaning of "disc jockey" was a person who played recorded music on a radio station and provided live spoken commentary between songs. Nowadays such a person is called a "radio personality".)
A disc jockey (abbreviated D.J. or DJ) is a person who mixes recorded music for an audience. Originally, "disc" (sometimes spelled "disk", although this is now uncommon) referred to phonograph records, not the later compact discs. Today, the term includes all forms of music playback, no matter the medium.