Memory Maker is just a new version of the PhotoPass+ you might be familiar with.
Buying Memory Maker gives you access to all the photos of you and your travel companions taken by PhotoPass photographers around the parks, plus attraction photos, and also your character meal photos. At the end of your trip, you can edit (make black and white, for example), decorate (add borders or character signatures, etc), and finally, download all your photos. You do NOT get a cd with Memory Maker - you download your photos directly from their site. You can then print them however, whenever, and wherever you want. You can also share them on social media sites and such. You can even burn them to your own disc at home, if that's your preferred storage for photos.
I hope that explanation helps...