The changes to Dynamics with the release of Dynamics 365 are numerous and exciting, however the licensing changes are also a topic to be highlighted. After November 1st, 2016, any Dynamics CRM Online renewals will need to be switched over to the new Dynamics 365 licensing model, which are slightly more complicated, but with the benefit of usually lowered costs due to tailoring licenses to functionality requirements on a per-user basis.
Hopefully this post will help guide you through the new licensed components, plans, and tiers for Dynamics 365 Enterprise Edition. (Note this will not pertain to Business Edition).
Once you understand the licensing components, take a look at the Dynamics 365 Pricing Calculator to play around with pricing.
More details on the specific actions in Dynamics 365 associated to these Subscriptions is available here on the Use Rights Breakdown.
Dynamics 365 Business Apps
At a high level, Dynamice 365 is essentially Dynamics CRM + Dynamics AX. There are some other distinctions however that can make it a bit more complicated from a planning an licensing perspective. In slightly more detail, here are the Business Applications in Dynamics 365:
PowerApps
Similar to Microsoft Flow (and based on the same underlying Azure Logic Apps), PowerApps allows users to easily integrate Dynamics 365 with other platofrms, as well as build custom apps that can make it easier for users to view and interact with data.
Sales
The Sales Business App is essentially the Sales related entities and components from Dynamics CRM, most easily summed up in this image:

Field Service
Field Service was a new addition to Dynamics CRM, added in mid-2016, which allows you to associate time with any record type in CRM, and can be used to schedule work or tasks in the field to available resources (such as employees, equipment, locations, etc). More information is available here.

Customer Service
All the same components available under the Service area of Dynamics CRM.
.png.aspx)
Project Service Automation
This was released as a managed solution, fully developed by Microsoft, in early 2016, and has been receiving improvements frequently after its release. It includes the Project, Time Tracking/Entry, and similar entities within Dynamics CRM.
More information is available on our other posts here and here.

Operations
The Operations component of Dynamics 365 will be Dynamics AX for Enterprise customers. Since this initial release, and subsequently this post, relate only to the Enterprise edition, we'll not be covering Dynamics 365 Financials (previously called Project Madeira) which is available in the Business edition of Dynamics 365.
Subscription License Types
Team Members
One of the biggest changes to licensing Dynamics 365 is the addition of Team Member Subscription Licenses, which come at much lower cost, and are meant for users who may need generic or light access to CRM, but most likely won't be working in it daily. These users will be able to work with Accounts, Contacts, Notes, and Activities, as well as some of the Time & Expense related entities.
More details on the exact functionality available to Team Members is available here.
Plan 1
All the Business Apps besides Operations are available in Plan 1.
.PNG.aspx)
Plan 2
All the Business Apps, including Operations, are available in Plan 2.

Now that you have a better understanding of the Business Apps, Plans, and License Types available, you can try out the Dynamics 365 Pricing Calculator to compare prices!