Re social login buttons generally...

Im trying to understand a fundamental thing about social login buttons but cannot find an answer to my question on the web. Q: Am I right in thinking that when someone create an account using any social login button - that only the username is transferred from FB/LinkedIn/G+ etc to the host WP database - ie NEVER the password. Im asking as using the social logins creates the account fine - but I can only ever login using the social login button and not the normal Username and password whcih keeps saying 'not recognised'. When I try to fix this missing password from the front end profile settings I can't - I must go to the WP admin and enter it there. Any help welcome.