title: How can QR code store so much data?
body: <p>Quick googling result that QR code can hold nearly 3kb (8 bit) data. But isn't it just using black/white dots to represent bits? If so there's no way that there's over 20,000 dots on a code.</p>
  
  <p>So I'm obviously misunderstanding. Can someone explain how it works?</p>