What really happens when you tap your credit card?

It’s an action you perform without a second thought: tapping a small piece of plastic to pay for your coffee. But in the two seconds it takes for the payment to be approved, a secret, high-speed conversation happens across a global network. How does this system actually work? How does it know you're you, keep your money safe from thieves, and move money from your bank to the store's, all in the blink of an eye? We trace the incredible journey of a single credit card transaction, from its surprising origins in a forgotten wallet to the powerful fraud-detecting AI that protects you today.