Authorisation is the module where you control the granular user permissions to access your projects, processes and brainstorms this helps you control who can access what and what they can do when they can access it.
User Manager is the module where you set up your users for the modeler and viewer plus you can set your security features such as IP restriction or HTTPs only traffic.
1 concurrent user means you are licensed to have 1 person logged into Engage Modeler at any time. If a second user tried to access at the same time they would be presented with an error message and would not be able to log in.
Support mails are email version of support calls.