QR codes can carry various types of information and be read by QR code readers or scanner apps on smartphones. They were created in 1994 and can hold data in both horizontal and vertical patterns within a black and white square-shaped grid. QR codes have finder and timing patterns to help scanners identify and read the code, as well as error correction data to account for distortions. Information like URLs, texts, contact info or WiFi networks can be encoded within a QR code to be scanned and accessed on a smartphone. QR codes have various uses in education like linking to course materials, maps, videos or surveys.