An authorization method is a scheme the client application uses to gain access to account information. AdWords, DoubleClick Ad Exchange Buyer and DFP APIs support several authorization methods including ClientLogin, OAuth1.0a and OAuth2.0. If you are still using an email address and a password to access the API, you are using the ClientLogin method which is now deprecated and is scheduled for sunset.
In a previous blog post we’ve covered general aspects of OAuth2.0 authorization and its benefits. To describe the process in more details, we’ve created a new article that shows how to use it with our official Ruby client library.
As always, please feel free to ask any questions regarding the client libraries or the AdWords API on our forum or during scheduled office hours. You can also follow the Google Ads Developer page for all Ads-related updates.