You might swipe your credit card several times a day, but did you ever wonder what those numbers on it mean? Those sixteen to nineteen, raised numbers, glistening in the sunlight... They're more than just means to buy groceries at the supermarket, or a gadget online.

These posts break it down for you:

What A Credit Card's First Digit Means
What Goes Into A Credit Card Number?
How They Check To Make Sure Your Credit Card Number Is Right

— BEN POPKEN