ISO files are disk images of physical disks like CDs and DVDs.
Disk images are perfect software copies of a physical disk like a CD, DVD or hard disk. A disk image contains all of the data on a physical disk with an identical file structure. The ISO format is a very common format for disk images. Mac programs often use the CDR or DMG format for disk images, however cross-platform downloads as well as CD and DVD disk images may come in the ISO format. The Finder in the Mac OS X operating system can mount ISO images.
Step 1
Locate the ISO file in the Finder.
Step 2
Double-click on the ISO file to mount it.
Step 3
Go to the "Devices" menu on the left side of the Finder and click on the ISO file to view the contents in the main Finder window.