A logical entity in Enterprise Single Sign-On (SSO), defined by the administrator, that represents a system or subsystem such as a host, back-end system, or line-of-business application to which you are connecting using SSO. An affiliate application can represent a non-Windows system such as a mainframe or UNIX computer. It can also represent an application such as SAP, or a subdivision of the system, such as the "Benefits" or "Pay stub" sub-systems.