Chill out (sometimes also chillout, chill-out, or simply chill), a term derived from a slang injunction to relax, emerged in the early and mid-1990s as a catch-all term for various styles of relatively mellow, slow-tempo music made by contemporary producers in the electronic music scene. The genres associated with chill-out are mostly Ambient, Trip-hop, Nu jazz, Ambient House, Ambient Trance, New Age and other sub-genres of Downtempo—a major branch of electronic music. Sometimes the Easy Listening sub-genre Lounge is considered to belong to the chill-out collection as well.
The term "Chill out music", as well as the genre itself, originated in chill rooms that were set up by DJs off to the edge of club dance floors to give patrons a chance to take a break from the hectic dance vibe and chill out with this style of music. Chill out as a musical genre or descriptive is synonymous with the more recently popularized terms "smooth electronica" and "soft techno" and is a loose genre of music blurring into several other very distinct styles of electronic and lo-fi music.