How Access and Refresh Tokens Work

Ever wondered how apps like Netflix and Facebook keep you logged in for months without ever asking for your password again? I used to just take it for granted - until I actually dug into how it works under the hood. Turns out, two small things are responsible for that seamless experience: access tokens and refresh tokens. Let's break it down. Modern apps don't pass your username and password around with every request. That would be like showing your passport every single time you walk through a door inside a building you've already entered. It's unnecessary, and honestly, a huge security risk. Instead, protocols like OAuth 2.0 and OpenID Connect (OIDC) use tokens. You prove who you are once, get a token, and that token does the talking for you from that point on. Here's the simple version of what happens when you hit "Login": You make a request to the app — say, "Login with Google." The app reaches out to an Authorization Server (Google, in this case), which checks your identity and ha