Relying Party (RP)
When you build an application that relies on claims, you are building a relying party (RP) application. Synonyms for an RP include “claims aware application” and “claims-based application”. Web applications and Web services can both be RPs. A relying party (RP) application consumes the tokens issued by a Security Token Service (STS) and extracts the claims from tokens to use them for identity related tasks. The STS supports two types of RP application: ASP.NET Web applications, and Windows Communication Foundation (WCF) Web services. WIF offers functionalities to help you build RP applications. For more information, see How to: Build an ASP.NET Relying Party Application and How to: Build a WCF Relying Party Application.