OAuth 2.0 is the next evolution of the OAuth protocol which was originally created in late 2006.
OAuth provides a method for clients to access server resources on behalf of a resource owner (such as a mobile device or an end-user). It also provides a process for end-users to authorize third-party access to their resources without sharing their credentials.
OAuth 2.0 focuses on client developer simplicity while providing specific authorization flows for web applications, desktop applications, mobile phones, and living room devices. This specification is being developed within the IETF OAuth WG and is based on the OAuth WRAP proposal. OAuth is an open standard for authorization.