This was great; very helpful.
I think this:
Redirect URI : The URL the Authorization Server will redirect the Resource Owner back to after granting permission to the Client . This is sometimes referred to as the “Callback URL.”
would be clearer if it was this:
Redirect URI : The Client URL the Authorization Server will redirect the Resource Owner’s browser back to after granting permission to the Client . This is sometimes referred to as the “Callback URL.”