About multi tenancy

Many b2b apps allocate one subdomain per customer. For example, if my domain is example.com, I may allocate one subdomain per customer like client1.example.com, client2.example.com and so on (clientN can also be the client's name instead)...

In this case, there are two choices for architecting login:

One login, many sub domains: A site may have one login page on example.com/auth or on login.example.com using which all customers can signin / sign up. If clientN signs in, they will be redirected to clientN.example.com.
One login per sub domain: A site may provide one login per customer domain. So clientN logs in via clientN.example.com/auth and after signin, they are redirected to clientN.example.com.

SuperTokens supports both the methods. Please see the next pages to learn more.