Explanation
An authentication scheme is a rule that determines if a user is authorized to access a specific component or feature of an application, such as a page, region, button, item, etc. An authentication scheme type defines how users are authenticated when they access an application. The authentication scheme type that supports authentication with social networks and enterprise identity providers that support OpenID Connect or OAuth2 standards is Social Sign-In. Social Sign-In supports authentication with Google, Facebook, and other social networks that support these standards. The other authentication scheme types do not support authentication with social networks or enterprise identity providers. They are:
HTTP Header Variable: Authenticate users externally by storing the username in a HTTP Header variable set by the web server.
SAML Sign-In: Delegates authentication to the Security Assertion Markup Language (SAML) Sign In authentication scheme.
Open Door Credentials: Enable anyone to access your application using a built-in login page that captures a user name. Verified References: [Understanding Preconfigured Authentication Schemes - Oracle Help Center], [Social Sign-In - Oracle Help Center]