What Is a QR Code? How It Works and Where It Is Used
What is a QR code? This guide explains how matrix barcodes work, what error correction levels do, and how QR codes are used in payments, link sharing and business cards.
A QR code (Quick Response Code) is a two-dimensional matrix barcode. Black and white modules are arranged by a fixed rule so that a relatively large amount of information fits into a small area and can be read quickly by a camera.
Compared with one-dimensional barcodes, QR codes hold far more data and can still be recovered when partly damaged, thanks to error correction. The usual levels are L / M / Q / H — the higher the level, the more damage it tolerates, at the cost of slightly less payload.
Everyday uses include opening web links, adding contacts, scan-to-pay, device pairing, and sharing Wi-Fi credentials or digital business cards. Note that generating and reading a QR code involves no encryption, so sensitive content still needs a secure channel.