HI HomeJ,
The following link: https://softwaresupport.softwaregrp.com/doc/KM01162178 details exactly what you are looking for in the five modes, Isolated (the default mode), Client registration (for utilization of third parties outside of ALM such as OTA), Shared (a combination of isolated and client registration), Combination (which involves multiple and different deployments on the same system, and Switching between modes (uninstall and reinstall of the client is recommended here).

These are all detailed and explained greater within the knowledge document KM01162178. I suggest that you follow the link and obtain the document for greater understanding or if you do not have a user account to access these documents on the self help system, then you may request this document from your support group to obtain it for you.

I hope this helps,
Dan