In Alfresco, the multi-tenancy feature is pre-configured out-of-the-box, although it is not enabled by default.
When you install Alfresco, multi-tenancy is disabled. The multi-tenancy feature is automatically enabled when the first tenant is created.
Note: Only an Administrator user can create tenants.
However, if you wish to disable multi-tenancy, you need to delete all the tenants. Refer to Managing tenants.