Dear Teena,
Thank you so much for reaching out to us here at the Disney Parks Moms Panel with your great question about figuring out the difference between PhotoPass and Memory Maker!
This was very confusing to me also when they first came out with these products, so I understand your question.
Disney PhotoPass Service is a FREE service available to everyone, in which official Walt Disney World Resort PhotoPass photographers will take your photo both with their camera and also with yours if you'd like! That way, everyone gets in the photo and no one is stuck out of all of the pictures because you have to take the photo. If you choose to purchase those photos, you absolutely can!
Memory Maker adds even more value to this service, by basically freeing you up to make unlimited downloads all of your Disney PhotoPass photos for you to download and use. It also includes Magic Shots, select Character dining photos, stock photos for you to use in your albums, and so much more! Honestly, I think Memory Maker is totally worth it if you plan to purchase more than a few photos for your later use.
Hope that helps with your magical planning!
- Jan K.