The data inside the ISO image will be structured according to the file system that was used on the optical disc from which it was created.
Optical-disc images are uncompressed and do not use a particular container format; they are a sector-by-sector copy of the data on an optical disc, stored inside a binary file.
The data inside the ISO image will be structured according to the file system that was used on the optical disc from which it was created.
Any single-track CD-ROM, DVD or Blu-ray disc can be archived in ISO format as a true digital copy of the original.
Unlike a physical optical disc, an image can be transferred over any data link or removable storage medium.
Most Unix-based operating systems, including Linux and macOS, have this built-in capability to mount an ISO.
This also means that audio CDs, which are usually composed of multiple tracks, can not be stored inside an ISO image.
However, since 2011, various software has existed to write raw image files to USB flash drives.