A QR code (Quick Response code) is a two-dimensional barcode that any modern smartphone camera can read on its own: no dedicated scanner app required. Unlike a standard barcode, which only stores data along one line, a QR code stores it across a grid, both horizontally and vertically. That is the whole trick behind why such a small square can hold a full web address, a WiFi password, or a complete contact card: it uses two dimensions of space instead of one.
What can a QR code actually contain?
People tend to think of QR codes as a way to open a website, and that is the most common use by far, but the format itself does not care what kind of data it is carrying. The same black-and-white grid can encode:
- Website URLs: the most common use, and the only content type flexible enough to point anywhere
- Contact details as a vCard, so scanning saves someone straight to a phone's address book
- WiFi network credentials, so a guest joins without typing a password
- Plain text: a note, a serial number, anything that does not need to be a link
- Email addresses, phone numbers, and SMS messages, each pre-filled and ready to send
- App Store and Google Play links, often routed by device so iOS and Android land in the right store
- Calendar events, map locations, and several other structured formats
What changes between these types is not the QR code itself: it is what the scanning device does with the decoded text. A URL opens a browser. A vCard-formatted string prompts "add to contacts." The QR code is just the delivery mechanism; the format of what is inside decides the behavior.
How does scanning actually work?
Every QR code has three squares in its corners: the finder patterns: that tell the scanner's software where the code is, which way it is rotated, and where its edges fall, even if the photo was taken at an angle. Once the phone's camera locates those, it reads the grid, corrects for any misread modules using the code's built-in error correction, and decodes the payload. On modern phones (iOS 11 and newer, Android 8 and newer) this happens automatically in the native Camera app: point the camera, a small banner appears with the decoded content, and tapping it takes you straight there.
Static vs dynamic QR codes
There are two fundamentally different kinds of QR code, and the distinction matters more than any design option. A static code has its destination baked directly into the pattern: once printed, that content can never change. A dynamic code instead encodes a short redirect link; scanning it hits a server that looks up the current destination and forwards the scanner there, which means you can update where it points at any time without touching the printed code. ScanOrbit creates dynamic codes by default for this reason: see the full comparison for when a static code is still the better call.
