An ISO image is an archive format that stores the exact image of an optical disk such as CD-ROM, DVD-ROM, and so on. ISO files are commonly used to store content to be burned to optical media.
This section will describe how to extract data from an optical disk into an ISO file that can be mounted as a loopback device, and then explain ways to generate your own ISO file systems that can be burned to an optical media.
We need to distinguish between bootable and non-bootable optical disks. Bootable disks are capable of booting from themselves and also running an operating system or another product. Bootable DVDs include installation kits and Live systems such as Knoppix and Puppy.
Non-bootable ISOs cannot do that. Upgrade kits, source code DVDs, and so on are non-bootable.