Identity as a Service, is a cloud service that provides identity management and cloud based authentication. Identity Management is the organizational process for ensuring the user is who they say they are and providing the proper access rights to the user. Cloud based authentication is the means in which a user authenticates themselves.
"Maintaining identity services across a large company is a costly challenge, especially for enterprises with many subsidiaries and properties across the globe. Organizations are adopting IdaaS more and more these days to simplify the challenges of owning and maintaining a large-scale identity ecosystem."