What is a DMG file?

A file with a .dmg extension is an Apple Disk Image file and known as a Mac OS X Disk Image file. DMG file format is the most widely used disk image file intended to allocate applications and files among the Apple PCs. It’s very convenient to mount DMG files into a virtual drive or can use Apple Disk Utility software to open and view the content of DMG file format. The old version of IMG files used in Mac OS Classic is substituted by the DMG file format. DMG files are generated for Mac users and are not supported by Windows OS but users can access the DMG content in the Windows Operating system by using compression and decompression tools like 7-Zip, Pea Zip, etc. The DMG file extension is also used by the Oracle Export and Ingress tool for scrapheap files kept in the binary format of the Oracle database.

Brief History

The DMG file extension was developed by Apple and is mostly used on Macintosh computers. Mostly the DMG file is used to give the Mac devices the capability to install different types of files and software that initiate from the internet. The DMG file is fundamentally a mountable disc image that displays on your desktop when it is opened. The file comprises raw data that is generally both encrypted and compressed. Mac systems treat DMG in the same way they would treat a disc that was interleaved, and they instantaneously try to open or “track ” the file.

Technical Specifications of DMG File Format

  • Specially generated for Macintosh computers
  • Developed by Apple
  • File format is Binary
  • File Category is Disk Image File
  • Supported Program is MacOS
  • Can contain a partition table
  • May contain any kind of filesystem like HFS+
  • Functionality to compress the images

See Also