database design issue

There are three types of users. Admin, student and supervisor.
Admin has LoginId and password.
student has LoginId, password, email and enrolID
Supervisor has name, LoginId and password.
Now the following DB Schema I have designed.

Role (Id, Name)
User (id, RoleId)
Supervisor (Name,UserId)
Student(Id,UserId, enrolId, email)
Credential(Id,UserId, LoginId,Password)

Is the above Schema is correct or not?? Plz help me thank you