Session, single session, multi session
Session is the unit
of CD recording which includes lead in sector, program sector and lead out
sector. Each sector has its own directory file that contains the introduction to
the format of the current session. The directory file in multi session will
include the introduction to the format of the sector before.
session is the common burning method, this method can save space. Compact disc
is usually single session disc.
Multi session disc refers to disk with
two or more than two sessions. This type of burning method is very convenient.
The disk can be burned again if the CD-R has enough space. But the multi session
burning requires a 30MB space interval between each session. Thus, multi session
usually wastes space of disc. Compact disc with-CD Extra format is the disc with
This area is at the
beginning of the session that is used to store data on the disc size, starting
position of each Optical track, Optical track length and so on. The lead in area
of each sector would be 1 minute long.
The lead out area usually comes at the end of each session that
indicates the end, readable session or the length of the entire disc. The lead
out area of the first session on the disc is 1.5 minutes long and the lead out
area in other session is 30 second long.