Multi-tenant vs multi-user
Any system may have multiple users. In a multi-user system multiple users can use the application (e.g. Exact Synergy).
The term multi-user does not imply anything for the architecture of the system. On the other hand, while a multi-tenant system
is a multi-user system, multi-tenancy tells us something about the architecture of the system: namely that multiple users share
the same application and database instance. Note that it is possible to have a multi-user system, which is not multi-tenant.