Track (optical disc) Track (optical disc) On an optical disc, a track (CD) or title (DVD) is a subdivision of its content. Specifically, it is a consecutive set of "sectors" (called "timecode frames" on audio tracks) on the disc containing a block of data. One "session" may contain one or more tracks of the same or different types. There are several kinds of tracks, and there is also a sub-track index for finding points within a track. Blu-ray discs can also be written in a sequential, session based mode modelled on CD and DVD. A Blu-ray "track" refer to the entire physical storage
DVD+R DL DVD+R DL DVD+R DL (DL stands for Double Layer) also called DVD+R9, is a derivative of the DVD+R format created by the DVD+RW Alliance. Its use was first demonstrated in October 2003. DVD+R DL discs employ two recordable dye layers, each capable of storing nearly the 4.7 GB capacity of a single-layer disc, almost doubling the total disc capacity to 8.5 GB. Discs can be read in many DVD devices (older units are less compatible) and can only be created using DVD+R DL and Super Multi drives. DL drives started appearing on the market during mid-2004, at prices comparable to