Imagine you're at a coffee shop.

You order a drink and get a receipt - that's your access token. It proves you paid and lets you grab your drink.

But it expires fast - just like access tokens.

Now, here's the trick: You also get a VIP card - that's your refresh token.

When your receipt runs out, show your VIP card at the counter, and boom - they print you a fresh receipt, no reordering needed.

That's what happens behind the scenes in ASP.NET Core - your app uses the refresh token to quietly grab a new access token, without logging you out.

Easy, right?