O365 - Tenants - Types and Licenses

[Taen keren]

Hi 

Can someone tell me how many "Types" of Tenants (options) there is in the O365 system? :D - And how to get "Federated" Tenants 

Case 1

A Faculty have an EDU Tenant/subscription where Professors, Teachers, Students, and other Faculty Staff have an O365 license - the Faculty also have a "Business" Tenant/subscription for their Admin staff and other personnel.

How can the Faculty get only 1 license on their users so Teacher1 (which is already licensed in the EDU Tenant) use the same license in the Business Tenant? - so the Faculty doesn't need to pay for 2 licenses for that Teacher1?
Can the Faculty in their Business Tenant use the B2B Azure collaboration and "invite" all the users in the EDU Tenants? 

Case 2 
A Company based in the US have a Tenant/subscription - and they use the domain Contoso.com and they also have a branch Office in France, Europe.
The Office in France have their own Tenant and uses a subdomain of the US Domain like fr.contoso.com - there's no common AD - nor Trust between the 2 ADs  

Can the US-based company initialize some kind of a "Multiple" Tenant and create a "Sub-Tenant" underneath and "give" this Sub-Tenant to the Office in France, so the Office in France can Admin their own Tenant, independent of the US Tenant?   
  

[#2 · Accepted solution]

Commercial, Edu, Government and Non Profit are the main ones. Free tenants (I.e. Teams) could class as seperate too. Oh and personal (365 home)

Case 1
You could use Azure B2B here but would probably look to do a tenant to tenant migration and merge the two environments. AvePoint and BitTitan are two options here

Case 2
Yes, you can set up two tenants one with a root domain and another with a sub domain if you wanted to split out the management

https://answers.microsoft.com/en-us/msoffice/forum/msoffice_o365admin-mso_domains/new-tenant-with-a-...

Hope that answers your questions

Best, Chris

[#3]

Thx  @Christopher Hoard