An ISO file often called an ISO image, is a term commonly associated with CD and DVD burning. It is a complete copy of a CD or DVD, which means that if you burn an ISO file to a blank disc, you'll get the same files, folders, and properties as the original disc. If you can open an ISO file, you'll see Video_TS folder and Audio_TS folder, same as what's on a DVD disc. You can create ISO images yourself or download them from the Internet.