An ISO image is an archive file (a.k.a. disk image) of an optical disc using a conventional ISO (International Organization for Standardization) format that is supported by many software vendors. ISO image files typically have a file extension of .ISO but Mac OS X ISO images often have the extension .CDR. 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 to ISO 9660.

As with any other archive, an ISO image includes all the data of files contained on the archived CD/DVD. They are stored in an uncompressed format. In addition to data of the files it also contains all the filesystem metadata, including boot code, structures, and attributes. ISO image does not support multi-track, thus cannot be used for audio CDs, VCD, and hybrid audio CDs.

With this ISO image you can :

Distribution of software

Mount "virtual drives" which emulate physical CDs or DVDs, such as Virtual Computers. Better performance is achieved by running an ISO image since hard drive I/O is many times faster than CD/DVD drive I/O.

To use software titles that are written in such a way that they require a physical disk to be present in order to run. Games are commonly in this category.

For backup, such as PSP backups.

This is a tutorial on how to use DVD imager to create ISO image from DVD on Mac for free.

DVD Imager can be used to make a burnable DVD video image file from a DVD video disk that you have made using iDVD or other means.

DVD Imager can create a Video DVD disk image using one of these two methods:

• 1. a VIDEO_TS folder (a DVD with slideshow created using iDVD, copied from an iDVD created Video DVD, etc.)
• 2. the contents of DVD including the VIDEO_TS and AUDIO_TS, and additional files and folders (such as a DVD with slideshow created using iDVD, a Video DVD created using iDVD, etc.)

Step by step instructions for using DVD Imager

1. Use iDVD or some other Video DVD tool to create
          A.) a VIDEO_TS folder with muxed video and audio encoded in MPEG2, or
          B.) a folder with VIDEO_TS and AUDIO_TS folders and additional files and folders.
2. Launch DVD Imager
3. If you chose option A, be sure that VIDEO_TS folder mode is selected. If you chose option B, be sure that Disk Copy Mode is selected.
4. Drag the VIDEO_TS folder onto either the DVD Imager Dock icon or the DVD Imager window. If you chose Disk Copy Mode (option B), DVD Imager will use the AUDIO_TS folder and additional files and folders found in the same location (folder) as the VIDEO_TS folder.
5. Click "Create Image"..
6. Specify the location where you want the disk image to be placed (if this is the first time you've created a disk image with DVD Imager, or if a checkmark appears in "Prompt for New Location").
7. Enter the name of the DVD using only capital letters and underscores. This is the name that computer users will see when they insert your Video DVD into their computer
8. Wait.

You can now review the Video DVD disk image by using the Finder to mount the .iso image (double click) and DVD Player to play the DVD by specifying the location of the VIDEO_TS folder in the mounted image. You can also burn the image to a blank DVD disk.

DVD Imager doesn't have the ability to defeat commercial DVD video copy protection methods, so it can't be used to copy commercial DVDs. If you want to backup commercial DVD, you can use DVD-Library for Mac.