A barcode is a machine-readable code consisting of numbers or letters, typically displayed as a pattern of lines or squares. Barcodes are commonly used to identify products (UPC codes), accounts (for example, in loyalty cards) or tickets (for example, airline tickets).
To identify yourself to a system that uses a barcode scanner: Flex Input's barcode display can reproduce existing barcodes, so (for example) if you have a membership number but no longer have the original loyalty card, you can reproduce the barcode using Flex Input and save it on your phone.