A large consumer company is planning to create a community and will requ.

To allow customers to log in to the communitywith any of their social identities, such as Facebook, Google, or Twitter, the identity architect needs to use authentication providers for social sign-on. Authentication providers are configurations that enable users to authenticate with an external identity provider and access Salesforce resources. To ensure that Salesforce has only one user per customer, regardless of how many social identities they have, the identity architect needs to use the custom registration handler to link social identities to Salesforce identities. The custom registration handler is a class that implements the Auth.RegistrationHandler interface and defines how to create or update users in Salesforce based on the information from the external identity provider. The custom registration handler can also be used to insert or update personal details of the customers when they log in to Salesforce using their social identity. References: Authentication Providers, Social Sign-On with Authentication Providers, Create a Custom Registration Handler