This is a kind of mixed CD. This CD has two or more than two data sessions. Each session contains complete file record and information. Two data session can adopt different file format of different operating systems. (Four types at present: DOS/Windows, HFS, Unix, and OS/2). The usually used Hybrid disc is DOS and MAC file format (DOS adopts ISO-9660 file system, MAC adopts HFS file system).
The shared Hybrid CD can be used on two and more than two operating systems, different system can read out the same data on CD-ROM. This type of CD has only one data area, all related data and files used by system are stored in the same data session. However, users can only check DOS files on DOS system, and MAC files can be seen on MAC system.
The following image shows the relations between format and file systems.