DMG files are files that are treated like actual hard disks by the Macintosh OS X operating system. These files can be created with Disk Copy, burned to a CD or even mounted as a normal volume on Macintosh computers. They often contain raw blocks of data that are usually compressed for easier file management.
Some .dmg files may be encrypted in addition to being compressed, for added file security. These files are often used by software installers that download applications from the Internet to a user's computer.
The Oracle export and import utility, used by Oracle databases, also uses the .dmg file extension for database dump files that are stored a binary file format.
Nov 12, 2019 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. 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. Right-click or Command-click the file or folder you want to copy inside the Seagate drive and choose Copy 'name of the file or folder you clicked on'. Open the Seagate drive from its icon on the desktop. Right-click or command-click into an empty area of the drive, and choose Paste Item. Your file or folder will now be copied over inside the Seagate drive.
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If you have additional information about the DMG file format or software that uses files with the DMG suffix, please do get in touch - we would love hearing from you.