Hi SBS,
OpenID Connect is a profile of (i.e. a collection of conventions for using) OAuth2.0 to allow a third party identity provider to authenticate an identity wanting to enter an access controlled Web domain. OAuth2.0 was originally developed as an authorization protocol, to allow people to control access to Web resources, like their calendars or photos. OpenID Connect extends OAuth to authentication. Check out these links -
OAuth2.0OpenID Connect - for more information.
Hope that helps.