The OAuth tab is where you can configure your applications standard OAuth settings including the name and logo that will appear in the Passport flow for your users.
This is the most important configuration in this tab is the Scopes. Every scope represents an authorization request that will be presented to the user during the auth flow in Passport. These authorizations include access to profile information, connected accounts, provisioning wallets and more.
OAuth Config Screen
OAuth Settings Panel
The settings panel is a read only configuration for your application's Client ID (aka App ID) and Client Secret (aka App Secret).