ISO 9660 is the standard filesystem for use on data CDs. It is commonly known as “ISO” for short. An “ISO image” is a file that contains an ISO 9660 filesystem.
ISO 9660 has several restrictions that are similar to MS-DOS FAT, in particular with file names consisting of 8 characters, a dot and 3 characters (the details of the restrictions are different, though). There are two common extensions that among other things allow longer file names:
- Joliet allows 64 Unicode characters in a file name (UCS-2 only). It is supported by most unices and by Windows.
- Rock Ridge allows 255-byte file names and supports symbolic links, permissions and other traditional unix metadata. It is supported by most unices.