A DMG file is a disk image file used on macOS to distribute software. It's essentially a mountable image file that contains the installation files for the software. When you open a DMG file, it mounts as a virtual disk on your system, allowing you to access the contents.
Released in 2012, Adobe Creative Suite 6 (CS6) was the final "perpetual license" release from Adobe. Before the company pivoted to the Creative Cloud (CC) subscription model, CS6 represented the pinnacle of buy-it-once, own-it-forever software. adobe creative suite cs6 master collection dmg top