Full Registration, or Site Registration, is when the customer registers themselves using an SAP Customer Data Cloud site by providing verifiable identity information, enabling further identification and login sessions for that customer. There are several credentials that can be used, such as username and password, password-less phone number, or push authentication.
Lite to Full Accounts:
A Lite Account can be migrated into a Full Account if the correct Progressive Profiling settings are in place. A password is then created for the password-less Lite Account, and the customer account is automatically converted to a Full Account.