Like SAML, OpenID Connect is a protocol based on OAuth 2.0 that sends identity information from one service to another. Unlike SAML, OpenID Connect is built for today’s world of social networks.
Have you ever installed a new app and come across a prompt like “Log in with your Google account”? That app is using the OpenID Connect protocol.
When you sign in with Google, you’re not creating an account and another password. Only Google holds that information.