I am looking to add an option for users to log in with their Google account, and I am confused. What is the difference between adding Google as an Identity Provider and setting up Google SAML?

I set up the Google one and tested it in our test instance, but it couldn't authenticate me even though I used the email/login I use for Canvas. I can't find anything in the documentation explaining how to get Canvas to sync.

Error: Canvas doesn't have an account for user: (a bunch of numbers)