Copy Beveiligde Audio CD

An Audio CD that can play in a standalone Audio player but not on a PC.

These CDs are per definition NOT complying with the CD standards and rely on CD/DVD-ROM players getting confused.
There are a number of different copy protections out there.
Most of them rely on the fact that standalone audio players only look for audio tracks in the first session (per Redbook standard) whereas CD/DVD-ROM drives look for ALL sessions and tracks.  The copy protected CDs mostly contain one or more higher sessions with incorrect TOC data per session so that CD/DVD-ROM drives get confused (after all they have to obey the specs to be able to mount all correctly mastered CDs).
Another technique used is to introduce a lot of level 2 errors so that playing analogue audio is not affected but extracting audio is.  These CDs better not get scratched and they will ware out fast !!

Being able to extract audio data from these CDs relies largely on the CD/DVD-ROM drive !!  IsoBuster can only compensate when the CD/DVD-ROM drives allow for compensation.