what is an .iso file
An ISO file is a complete copy of a CD or DVD. You can create ISO images yourself or download them from the Internet. For example, Linux distributions offer freely downloadable ISO files that you can burn to disc. You can use an ISO image in a variety of ways. The ISO file itself is a backup of a disc, so you can use the ISO file if you ever lose or damage the original disc CDs Are Not Forever: The Truth About CD/DVD Longevity, Mold & Rot .