OAuth2 Authorization Code Flow Explained Without the Jargon

OAuth2 is an authorization framework that allows apps to access user data on third-party platforms without ever handling the user's password. Instead of credentials, apps receive a scoped access token — comparable to a valet key — granting limited, time-bound permissions on a user's behalf. For most web applications, the Authorization Code Flow is the only grant type developers need to understand, involving a four-step exchange between the browser, backend, user, and identity provider like Google or GitHub. The flow deliberately splits the process so that the sensitive client secret and final token exchange happen server-side, protecting against interception in the browser environment. A short Node.js example illustrates how the temporary authorization code received after user consent is traded server-to-server for the actual access token.