Because the ordinary CD player used for playing back music is not capable of multi-session operation, when multi-session formatted discs are played back in such players, they will recognize and play the first session, but cannot play the second. Making use of this characteristic, this type of CD-ROM format is structured to record the first session as an audio track and the second as a data track. When it is played back by a CD player, because the first session is an audio track, the disc will be identified as a conventional audio CD disc. When it is played back by a CD-ROM drive with a device driver that supports Enhanced CD, it is identified as a CD-ROM disc. On the other hand, with a device driver that does not support Enhanced CD, it is identified as an audio CD. This is because device drivers that are not configured for Enhanced CD recognize the difference between CD-ROM and Audio CD at the first track, so they recognize Enhanced CD, whose first track is audio, as an ordinary Audio CD. CD PLUS and CD EXTRA can be categorized into this format as well.

A term commonly applied to a type of CD that combines audio content suitable for playback on a CD player, as well as computer readable content, often inter-active multimedia presentations, that can be accessed when the disc is inserted into a computer's CD-ROM drive. A variety of implementations have been introduced, including CD Extra and CD Plus.

a CD that acts as a regular audio CD when placed in a CD player but when put into a computer, it has a CD-ROM aspect to it with an interface and content such as videos, web links or photo galleries

See CD Extra.