The iso file extension is mainly used for binary images of CD, DVD discs. The generic file format for most optical media, including CD-ROM, DVD-ROM, Blu-ray Disc, HD DVD and UMD.ISO 9660, a standard published by the International Organization for Standardization (ISO), defines a file system for CD-ROM media. It aims at supporting different computer operating systems such as Microsoft Windows, Mac OS, and systems that follow the Unix specification, so that data may be exchanged.