An ISO file is a common CD or DVD disc image format based on the ISO-9660 standard. It contains an exact duplicate of data from the original disc, which includes the data saved on the disc as well as the filesystem information, such as directory structures, file attributes, and boot code. ISO files are often used for making copies of CDs and DVDs.

ISO files are useful for duplicating or backing up CDs and DVDs because they copy every bit of data exactly from the disc. This is different than copying all files from a disc because the disc header information is lost in the copy process. An ISO file can be used to restore a disc exactly to the original version. Windows 7 includes a utility called Windows Disc Image Burner that can burn ISO images to CDs and DVDs. The utility is located in the WindowsSystem32 directory and has the filename isoburn.exe. NOTE: Some ISO files can be loaded by a Sony PSP using the Fast Loader utility.

ROM file that contains a complete copy of data extracted from a PlayStation 2 game; often used for making backup copies of PS2 games; can be opened with a PlayStation 2 (PS2) emulator such as PCSX2.

To open an ISO file with PCSX2, you can simply drag and drop the file to the application without mounting the disk image. You can also select CDVD → Iso Selector → Browse, navigate to your file, and click Open. In order to use PCSX2, you must "dump" the Basic Input Output System (BIOS) files from your PS2 console. It is illegal to use BIOS data from other PS2 consoles. NOTE: Because of their large file size, PS2 ISO game files may be compressed. Compressed ISO files may have a different file extension, such as .7Z, which indicates the type of compression used to reduce the file size.

An ISO file is a ROM file that contains a complete copy of data extracted from a Nintendo Wii game. It may be used by a Nintendo Wii emulator, such as Dolphin Emulator, to play a game. ISO files may also be used to store a backup copy of a game.

Since ISO files typically store an exact, uncompressed 1:1 copy of a Wii game, they are often very large in size. Many ISO files are compressed and may have a different file extension, such as .ZIP or .7Z, which indicates the type of compression used to reduce the file size. You can use a decompression utility, such as 7-Zip, Corel WinZip, or Apple Archive Utility to extract the ISO file from the archive. NOTE: Downloading ISO files containing Wii games is illegal. You should only dump Wii games from discs that you own to ISO files.