An Illustrated Guide to OAuth

This article provides an illustrated guide to OAuth, explaining its origin, purpose, and how it works. It details the OAuth flow from both a user's and a developer's perspective, introducing key terminology such as resource owner, OAuth client, authorization server, resource server, and scopes. The guide also covers security considerations, including why sending access tokens in URLs is not secure and the role of authorization codes and client secrets. It touches upon advanced topics like PKCE for apps without a backend and the distinction between front-channel and back-channel communication in OAuth.