It's an automatic process: download, move, delete (if necessary). It doesn't store the file and I think it's usually an .app file and not a .dmg. See this previous thread that discussed it: https://forums.macrumors.com/threads/1104397/As title says
Is there any chance to save the .dmg file?
You're talking about OS X updates? Just download them from Apple's site instead of through the Mac App Store, and you can copy the file from one computer to all the others.thanks for answering
although i'm still mad at apple for these kind of privacy and copy right stuffs.
in my case i've got limitation from my ISP in downloading.
for example downloading the same 1.6 GB update package for 3 or 4 macs repeatedly is not reasonable!!while i've paid for it and i have the right of having its installing file.