Hi,
See below:
Single sign-on (SSO) is a property of access control of multiple related, but independent software systems. With this property a user logs in once and gains access to all systems without being prompted to log in again at each of them. This is typically accomplished using the Lightweight Directory Access Protocol (LDAP) and stored LDAP databases on servers.[1] A simple version of single sign-on can be achieved using cookies but only if the sites are on the same domain.[2]
Conversely, single sign-off is the property whereby a single action of signing out terminates access to multiple software systems.
Andy
