The term originally came about in the early days of Top 40 radio formats when stations would devise (and, eventually, publish) a limited list of songs to be played. The term would go on to refer to the entire catalog of songs that a given radio station (of any format) would draw from. Additionally, the term was used to refer to an ordered list of songs played during a given time period.
As music storage and playback using personal computers became common, the term playlist was adopted by various media player software programs intended to organize and control music on a PC. Such playlists may be defined, stored, and selected to either run in sequence or, if a random playlist function is selected, in a random order. Playlists' uses include allowing a particular desired musical atmosphere to be created and maintained without constant user interaction, or to allow a variety of different styles of music be played, again without maintenance.