Using Single Sign-On, your users could get automatically authenticated while logged in to your common Login option. For example, if you have a website or dashboard where your users login and would like to use the same to access Freshdesk, you could make use of Single Sign-On.

You could configure Single Sign-On within Freshdesk from under Admin-->Security and turning on "Single Sign-On". You could then choose between Simple or SAML SSO to proceed with the configuration.