Have you ever logged into a website using Google or Facebook instead of creating a new password? That’s OAuth 2.0 in action. But how does it work and why is it secure? Let’s break it down with a simple example. Borrowing a book from a library. OAuth 2.0 allows apps to access user data without sharing passwords. It involves four key players. First, there’s the user. That’s you, trying to log in. Next, the client or the app you’re logging into. Then, the authorization server, like Google or Facebook, verifying your identity. Finally, the resource server where your protected data is stored. Now, let’s compare this to borrowing a book. You walk into a library, but before you can take a book, the librarian asks for your ID. Instead of handing you the book, they verify your identity. This is like when an app redirects you to Google or Facebook to log in. Once you provide your ID, the librarian checks it and gives you a library card. This card isn’t the book itself, but proof that you’re allowed to borrow one. In OAuth, this is called an authorization code. You then exchange this card for a book at a different desk.