SSO(Single Sign On)单点登录系统,是在多个系统中值要求只要登录一次,就可以用已登录的身份访问多个系统,去掉了每次访问不同的系统都要重新登录的弊端. CAS(中央/集中认证服务):The Central Authentication Service project, more commonly referred to as CAS is an authentication system originally created by Yale University to provid