CA Siteminder means Computer Associate's (CA) SiteMinder is an enterprise infrastructure product that enables centralised web access management system that enables user authentication and single sign-on, policy-based authorization, identity federation, and auditing of access to Web applications and portals. For eg: If an Organisation having the multiple websites it will provide the flexibility to their users by using one set of login credentials they can be allow to multiple applications with in that organisation this is called the single sign on. using the product of siteminder.