谷歌搜索 saml 2.0 site:cnblogs.com
基于SAML的单点登录介绍
https://www.cnblogs.com/zsuxiong/archive/2011/11/19/2255497.html
SAML2.0 协议初识（一）
https://www.cnblogs.com/xiaosiyuan/p/8080515.html
A Service Provider (SP) is an entity that provides Web Services. ... In the WS-Federation model a Service Provider is called a “Relying Party” (RP).
In SAML, the XML-standard for exchanging data, the security domains that information is passed between are a Service Provider (SP) and an Identity Provider (IdP).