# Part 1 - Introduction To OAuth
OAuth Simplified 1 / 4
10 min read
Why OAuth exists, the four components it introduces, and how delegating access works without ever handing over your password.
Why OAuth exists, the four components it introduces, and how delegating access works without ever handing over your password.
How a client redirects the user, trades an Authorization Code for an Access Token, and uses the state parameter to shut down CSRF attacks.
How a protected resource validates Access Tokens, enforces scope, and uses token introspection so it has to trust nothing the client sends.
How the Authorization Server registers clients, issues Authorization Codes and tokens, enforces PKCE, and what it stores and checks at every step.