This data can be propagated to the client requesting a login via the token or SAML assertion being passed back to it by using an appropriate client mapper.
This is the IDP username of the currently authenticated user. This is often the same as the {project_name} username, but doesn't necessarily needs to be.
For example {project_name} user `john` can be linked to the Facebook user `john123@gmail.com`, so in that case value of user session note will be `john123@gmail.com` .