CDR/W Writing Methods:
There are several ways to write to a compact disc. The one that’s used depends on bith the logical format and the physical format in wich the disc is written.
This is the so-called “gap-writing-method”. When a new track must be written, the CDR/W laser is turned on, when the track ends the laser is turned off, even when you are writing several tracks within the same recording session. Each recorded track will be seperated by a “gap”. The gap is 2 or 3 seconds for a data track, followed by and audio track. Gaps between audio tracks have a standard lenght of 2 seconds. However, if your recorder doesn’t choke on it, you can adjust the lenght of a gap. Nero, WinOnCD and Prassi Replicator (and others…) support this feature as long as your recorder supports it. Most new recorders do.
This method is used for CD-extra CD’s: The recorder will burn several audio tracks to the CD without turning the laser off, when all tracks are written the laser will be turned off. Next, the data track is being written, then the disc will be closed.
Disc-At-Once (DAO or RAW):
The Disc-At-Once operation requires a blank media to be inserted. One or more tracks are written to the disc without turning the laser off. When the tracks are finished recording, the disc will be closed. This method can eliminate the 2-second gaps when writing a Audio disc. Please note that not all recorders support this feature.
[grabbed from their site]