ISO 9660
Updated: 09/03/2019 by Computer Hope
The first standard used for data CDs on PC or IBM compatible computers. Unfortunately, in the beginning, many manufacturers had an implementation of this loose standard. The ISO 9660 standard is constantly being upgraded and tightened to include new methods. The most important standard factor is when a disc has audio and data that the data is placed before the audio. This was originally called High Sierra.
Note
Apple Macintosh CDs use HFS (hierarchical file system), the same file system used with their other disk drives.