Android :What is the difference between app signing certificate and upload certificate?

Question

What is the difference between app signing certificate and upload certificate? I am having trouble with integrating Google Play Games with my app (I posted about this as another question) and I noticed that the one that is used for client Id that is automatically generated on Google API Console is called signing certificate.
However, what I can see when I run signing in report on Android Studio is called upload certificate.

Which one is supposed to set for client Id? By the way both didn't solve my problem but I am curious about the difference.

Answer 1

Signing certificate

Certain Google Play services (such as Google Sign-in and App Invites) require you to provide the SHA-1 of your signing certificate so we can create an OAuth2 client and API key for your app. For more info refer:doc

Upload certificate

When you publishing an app that is not signed by an upload key, the Google Play Console provides the option to register one for future updates to the app. Although this is an optional step, it’s recommended that you publish your app with a key that’s separate from the one Google Play uses to distribute your app to users. That way, Google keeps your signing key secure, and you have the option to reset a lost or compromised private upload key. This section describes how to create an upload key, generate an upload certificate from it, and register that certificate with Google Play for future updates of your app. For more info refer:doc