compact disc extra (CD-Extra)
CD-Extra is essentially the same as a mixed- mode CD and contains one data track and one or more audio tracks. However, in CD-Extra the audio tracks are written in the first session and the data tracks are written in the second session according to CD-ROM/XA.
CD-Extra is a CD standard defined in the Blue Book that is especially suitable for multimedia.
The CD-Extra is the successor of the CD-Plus, which is also sometimes called CD+. The audio tracks of the CD-Extra, which are in the first session, can be read by a normal audio CD player without any problems. The data tracks that follow the audio tracks can be read by multisession CD drives.