Topic summary
DJ

Extracted from the Wikipedia article Disc jockey.
Role
"DJ" is used as an all-encompassing term to describe someone who mixes recorded music from any source, including vinyl records, cassettes, CDs, or digital audio files. DJs typically perform for a live audience in a nightclub or dance club or a TV, radio broadcast audience, or an online radio audience. DJs also create mixes, remixes, and tracks that are recorded for later sale and distribution. Some DJs adopt the title "DJ" as part of their names. Professional DJs often specialize in a specific genre of music, such as techno, house, or hip-hop. DJs typically have extensive knowledge about the music they specialize in. Many DJs are avid music collectors of vintage, rare, or obscure tracks and records. An unreleased (or otherwise unnamed) track played or published by a DJ is known as an "ID". The term "ID" is additionally used to refer to an artist whose identity is unconfirmed (in reference to the author of an anonymous track), often with the possibility their name will be revealed at a later date.