How QR codes actually work (without the jargon)

A QR code is just a way of writing text that cameras read more reliably than letters. The black-and-white squares are bits — on and off — arranged in a grid your phone decodes in a fraction of a second.

The parts of a code

• Finder patterns: the three big squares that tell a camera where the code is and how it's rotated
• Data area: the speckled middle where your actual content lives
• Error correction: spare copies of the data so a code still scans even if it's scuffed or partly covered

Why error correction matters

You can choose how much redundancy a code carries. Higher error correction means the code survives more damage — useful if you're adding a logo or printing on packaging — at the cost of a denser pattern.

That's really all there is to it: structured dots, a bit of redundancy, and a camera that knows the rules. The clever part is what you point them at.