ARCHIVED: What is an ISO image?

This content has been archived, and is no longer maintained by Indiana University. Information here may no longer be accurate, and links may no longer be available or reliable.

An image is a file that copies an original piece of media, whether an ISO, floppy, or other media image. This file not only contains individual data files, but also track and sector information; it arranges all this information in a file system, just like disk media. Image files, unlike normal files, are usually not opened; rather, they are mounted.

An ISO image is a CD-ROM or DVD image saved in ISO-9660 format.

ISO images are often used as source files from which to create media: After you download an image, you can use disc-burning software to recreate the physical CD-ROM or DVD (e.g., as backup install media). Alternatively, you can mount the image to access the content within it.