Barcode
Newer 2D systems use symbols other than bars and can hold more information, but they are also called barcodes. They need to be scanned left or right, and up or down (two directions). QR codes were invented in 1994 to use in factories to track parts and products. People use them for many purposes in the 21st century. Special software can read QR from an image. Smartphones can have an app to show and read them. This is becoming increasingly popular as more apps are able to use such features to help the user obtain access to websites and special resources, such as being used in 'digital cities', such as Bordeaux. Many kinds of tickets, including those for transport, have a QR code.