OAuth 2.0 is an authorization framework that enables applications to obtain limited access to user accounts on an HTTP service, such as Facebook, GitHub, or Google. It works by delegating user authentication to the service that hosts the user account and authorizing third-party applications to access the user account. OAuth 2.0 provides clients a "secure delegated access" to server resources on behalf of a resource owner. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) training