When you’re done installing the application, it’s a good idea to unmount the DMG in Finder when you’re done installing: just click the “Eject” arrow. DMG files are mounted by your system, like a sort of virtual hard drive. Move files that you want to keep into another folder and delete files you no longer need. Now Empty the Trash to recover the disk space. Dmg files to the Trashcan on the Dock or select all of them and press COMMAND- DELETE to move all of them to the Trash. Disk Images are generally used worldwide in-order to distribute applications and software across the Internet. The icon used equivalent to this file is an Internal Hard-drive. DMG file can also be termed as Apple Disk Image. In computing world, DMG or (Disk Image File) is a file extension that belongs to Mac OS X. If the DMG has a virtual drive mounted, then you cannot delete it because it is still open. You must 'eject' (or unmount) the virtual drive, then you can delete the DMG file from your computer. A DMG is like a ZIP file, but it mounts a virtual drive on your desktop for installation.
Mount, an entire Disk Image, or delete it in entirety (as a Disk Image itself is a single large file). This is a different concept than file permissions: File permissions allow you to read, i.e. You can edit, add, and remove files on a Disk Image if it is formatted to be readable and writable, which is set at the creation of the Disk Image.
