Previously while accessing Zoho services, users had the liberty of accessing all the Zoho Apps (except Zoho CRM) with a single User name and password. With this release, Zoho CRM becomes a part of Zoho SSO. This means users once created within the Zoho CRM need not create a different account (User name and password) for accessing other Zoho services and vice versa.

To know more on this refer : SSO Transition Guide

Victor