[Mailman-Developers] REST API Difference between PUT and PATCH?

The user endpoint supports PUT and PATCH methods.

PATCH does a partial update of the user’s configuration

PUT does a full update of the user’s configuration

It seems that for user, the field that can be modified between these two methods are display_name and cleartext_password

What is the difference exactly between partial and full update?

Are the two fields required in one case and optional in the other?

thanks