Single
In music, a single is a type of release of a song recording of fewer tracks than an album or LP record, typically one or two tracks. A single can be released for sale to the public in a variety of physical or digital formats. Singles may be standalone tracks or connected to an artist's album, and in the latter case would often have at least one single release before the album itself, called lead singles.
The single was defined in the mid-20th century with the "45" (named after its rotational speed), a type of 7-inch sized vinyl record containing an A-side and a B-side, i.e. one song on each side.