IT:AD:SSO

When accessing different applications owned by different organizations, having to authenticate every time you go from one application to another is annoying.

Single sign on is the ability to authenticate once and be able to move between applications seamlessly using the authenticated Identity/.

Within a corporate intranet SSO can be easily implemented by generating a sessionid and passing it around using cookies.

However, such a solutions are proprietary. To inter-operate with applications beyond the intranet, a more standards based solution is required.

SSO is a subset of IT:AD:FIdM, as it relates only to authentication and is understood on the level of technical interoperability.