With disk image files, you can also create a image file of a CD, and that can be used to create a CD that is identical to the original CD. For example, you can create a zip version of all files on a CD, but that zip file can't be used by the OS to boot the machine. The OS will treat disk images just like a storage device, but a virtual one. Disk image is roughly a copy of the actual structure of disk. “.dmg” file are files in Apple's disk image file format,įiles are different than compressed files. Line tools for Mac specific things, such as launching apps, put system to sleep, etc. This document explains Mac OS X's “.dmg” file, and some tips about using command
