DMG File

A file with the extension .dmg which uses a proprietary disk image format commonly found on Mac OS X.

What is DMG file?

DMG stands for disk image. It is a format commonly used to distribute files and applications among Apple computers. A DMG file is like a virtual DVD or hard drive. DMG files can be “mounted” on your Mac to work with their contents. They can even be burned into an actual physical disk.

In order to understand the concept of a DMG disk image, think of a storage volume such as a CD, DVD, hard drive, or external hard drive. A DMG file is like one of these devices in that it serves as a means to encapsulate documents, images, software, and other files. The difference between a DMG file and those mentioned above is that with a DMG, there is no physical storage medium.

Once you are done working with the contents of a DMG file, you will want to remove or “unmount” it from your system. Do this by opening the Finder and clicking the eject icon shown next to the virtual drive’s icon. You can also do this by going to your desktop, clicking once on it’s icon, and pressing CMD+E.

How to open DMG file?

DMG file represents disk image format commonly found on Mac OSX. This format allows secure password protection as well as file compression and hence serves both security and file distribution functions. Its most common function is the distribution of software over the Internet. When opened, DMG files are "mounted" as a drive within the Finder.

DMG files are Mac-specific and are not intended for use in Windows; however, Windows Daemon Tools may be able to mount virtual drives from some DMG image files; other utilities may also be able to convert DMG files to a format that can be recognized by Windows.