What is a QR code?

A QR code (short for Quick Response code) is a two-dimensional barcode: a grid of black and white squares that stores information. Point a phone camera at it and the phone reads the pattern and acts on it — opening a website, saving a contact, joining Wi-Fi, and more. Unlike the striped barcodes on groceries, a QR code stores data both horizontally and vertically, so it can hold far more in a small space.

The pattern encodes data as a sequence of light and dark modules. A few parts are always there: three large squares in the corners help the camera find and orient the code, smaller alignment marks keep it readable at an angle, and built-in error correction lets the code still scan even if part of it is dirty, damaged, or covered by a logo. When your camera sees a valid pattern, it decodes the data and offers the matching action.

This is the most important distinction. A static code stores the data directly in the pattern — it's free and permanent, but it can never be changed and can't be tracked. A dynamic code stores a short redirect you control, so you can change where it points after printing and see how often it's scanned. If there's any chance your content will change, or you want analytics, choose dynamic.

On most modern phones you just open the camera app and point it at the code — a link appears to tap. Some older phones need a dedicated QR scanner app. No special hardware is required.

You'll find them on restaurant tables (menus), product packaging (setup guides), business cards (contact details), posters and flyers (campaign links), event badges (agendas), and store windows (after-hours info). Because a dynamic code can be updated, a single printed code can serve a whole campaign.

Rules of thumb are a starting point. Phones, printers, finishes, curves, lighting and viewing distance change the result. Test the final artwork on the final material and keep a record of the approved version.