It's really not all that complicated, although Disney didn't help anything with their choice of terminology. There are 3 components of "Disney Genie".
Genie is the new add-on to
MDE that will provide real time info on wait times and make suggestions to you as to what you should do next (based on criteria you establish). This is free to all guests.
Genie + is the name of the new fastpass system. This is essentially the MaxPass system that was in use at
Disneyland. This will cost $15/day per person and you can purchase it for only the days you want to use it. This will give you access to the
Lightning Lane (new name for the fastpass queue). You can hold only a single LL pass at a time, and can only book them the day of your visit. Genie + is available for all the existing fastpass attractions EXCEPT the top two attractions in each Park. Like FP+, availability will be limited.
Individual Paid Attractions: these are the top two rides in each park. There is still a stand by queue (or boarding group) for these, but if you want to use the Lightning Lane, you have to pay extra for that. Pricing has not been announced but it will depend on the day, the crowds, and the time. Anyone can purchase this option, whether you have purchased Genie + or not. You can purchase
only 2 of these per day. Availability of slots for this option will be limited as well.
There are more details to come and the nuances are unknown at this time, but this is a brief summary as of now. Hope it helps some.
Steve