IMG file format, which was previously used in Mac OS Classic. Some programs include 7-Zip, PeaZip, and DMG2IMG.

While DMG files are Mac-specific and not intended for use in Windows, there are several Windows programs that can extract their contents or convert them to other formats. Therefore, DMG files can be deleted after installing the software. The file extension means Disk Image and is proprietary to Apple. Or the Mac user can drag the program icon to the 'Applications' folder icon to move it to the 'Applications' directory in macOS.Īfter the software stored in the DMG file is installed, the DMG file is no longer needed. dmg file is a copy of a physical disk, such as a CD or DVD, contained in a single file. In the Finder window, the Mac user can double-click the program icon, which is an APP file, to run the app. When the DMG file is opened, it mounts a virtual disk on the desktop and in an Apple Finder window as if it was a CD or a USB flash drive that was just inserted into the computer. When a Mac user downloads a DMG file, he can simply double-click it to open it with the DiskImageMounter utility that comes with macOS. DMG files are especially common since their contents can be verified upon installation to ensure they have not been tampered with and they can also be compressed to reduce the size of the installer. Today, software developers typically build and distribute applications for Mac users as DMG.