What is OAuth 2.0 authorization code flow and when would you use it?

The OAuth 2.0 authorization code grant can be used in apps that are installed on a device to gain access to protected resources, such as web APIs. Using the Microsoft identity platform implementation of OAuth 2.0, you can add sign in and API access to your mobile and desktop apps.

The flow enables apps to securely acquire access tokens that can be used to access resources secured by the Microsoft identity platform, as well as refresh tokens to get additional access tokens, and ID tokens for the signed in user.