Um, you're kinda on the money with that answer......, however, in the case that he brings it up (for cd backup images of DC games) the multisession is purposely added to allow the game to be self bootable. The first session is burned in CDDA (CD audio format) which this session only uses a small portion of the entire disc. That session serves no other purpose than to make the DC boot the game. That session is closed out and a second session is burned with a new lead in (beginning of a new session) and this is done in Mode 1 format (mode 1 is a standard sector and track layout for information discs (CD-ROM). This is the session that actually contains the game data. This session is also burned with a lead out (finalized) and this procedure creates a CDR copy of a DC game that is bootable by using an exploit that was discovered which allows normal CD's to instruct the DC bios to boot the disc.
You are right as well Whirlwind, as far as standard multisession goes with a burning application, but there are also other types of multisession than one that allows you to add other tracks at a later time. In the case of a CDR backup, the two separate sessions are burned in one process. So no need to eject the disc after the first session is burned before you burn the second session.
