Relying Party
Relying party or third party is a computer term used to refer to a server providing access to a secure software application. Claims-based applications, where a claim is a statement an entity makes about itself in order to establish access, are also called relying party (RP) applications. Actually RP refers to the person who provides services to the customer not directly but just by connecting the customer to the actual seller. Usually, the host or the merchant has to identify the real party that is delivering services to the customers.