I. What is ISO Image? An ISO image is an archive file (also known as a disk image) of an optical disc in a format defined by the International Organization for Standardization (ISO). This format is supported by many software vendors. ISO image files typically have a file extension of .iso. The name ISO is taken from the ISO 9660 file system used with CD-ROM media, but an ISO image can also contain UDF file system because UDF is backward-compatible with ISO 9660. II. How to Copy DVD Movies to ISO Image on Mac? III. How to Play ISO Image on Mac for free