A QR code (Quick Response code) is like a barcode on steroids. It's a square image that stores information as a pattern of black and white pixels. You've probably seen them used for everything from making payments to accessing Wi-Fi networks. When scanned with a smartphone camera, the QR code can quickly access a website, download an app, or reveal information. They are popular because they are easy to use and can store much more data than traditional barcodes.