Recording in disk-at-once mode writes the complete disc, i.e. lead-in, one or more tracks and lead-out, in a single step. The commonly used track-at-once (TAO) mode writes each track independently which requires link blocks between two tracks. Older CD-recorder models forced a two second pause (pre-gap) between two tracks whereas newer models allow adjusting of the pause length in TAO mode reducing the number of link blocks to a minimal amount.
