The difference is that the DMG file itself remains on your computer, unlike a CD-ROM that is removed when ejected. These files mimic the function of a physical disk, and behave similarly in that the system interprets you opening them as if you have just inserted a CD-ROM into your computer, and to close them you simply eject them as you would disconnect an external drive or eject a CD-ROM. If they just allow the software to be downloaded as is, then corruption may happen to it in transit it can also be tampered with as it resides on the developer's servers.ĭisk image files (of which DMG is one type) help prevent these problems by offering a way to package data in a relatively secure manner. These days, with broadband Internet, software can be more readily downloaded, but developers still have to ensure the software is received intact. Traditionally software has been distributed on physical media, like CD-ROMs, which are read-only and ensure the software on them is as the developer intended. At other times when I download an application I open it and it seems to work, but when I restart my system I can't find the application anymore.'

'How do you use these DMG files properly when downloading applications? Sometimes when I download apps a DMG file opens and there are instructions to install the program when I open it. MacFixIt reader Mary wrote in with a question about this: The file will likely be named similarly to the application, and some people may be a bit confused about how to properly use what they have downloaded. dmg file instead of the application itself. When you purchase an application or download it from a the Internet, often it will download as a.

Can you delete dmg files