Its done its job and is only taking up disk space now. Yes you should trash it if you have loaded the software. Reboot and if you can run the app, it’s safe to empty the trash. In this case, put the dmg in the trash but don’t empty it. It is safe if you want to delete these files, once your system is upgraded and their is no problem after upgrading your systems. Incomplete installation - some people run apps out of a DMG and don’t install the app drag and drop.archival purposes - just in case the original becomes unavailable for any reason & you might one day need to reinstall on a new Mac (if you have it backed up to Time Machine you can delete it sooner of course).The only two reasons to keep them would be for: dmg itself is no longer required & can just be deleted.
From the available document types that show up on the dialog box, select Service. Delete DMG Files Automatically When You Eject Them Step 1: Open Automator and choose to create a new document.
dmg arrives intact then you can be sure it arrived 'as sent' & can copy it to your Applications folder. Installers can be installing all sorts of files, all over your computer. A disk image file (.dmg) is simply an easy, portable structure to transfer an app to you without falling afoul of any internet 'oddities' such as compression, splitting etc.
