Which Authentication Policy is Stronger in ADFS?

ADFS support below authentication policy

• Windows based Authentication
• Form Based Authentication
• Certificate Based Authentication

Which Authentication Policy is Stronger in ADFS ?

If all policies are set which authentication will be given first priority ? Why ?

You tagged as ADFS 2.0 so I assume you are using that.

Good writeup here.

You can set the order in "localAuthenticationTypes".

By default, on the extranet (via WAP) it's Forms as it's non-domain joined so no WIA.

By default, on the intranet, it's WIA as it's domain-joined and providing the browser is configured to support WIA.