What is a barcode?  Barcodes (bar codes) are machine-readable symbols used to store bits of data. Barcodes are used for identification, tracking, inventory, and as part of retail point of sale (POS) systems. Barcodes are used everywhere in the modern world and are there if you look for them. Barcode is used to eliminate typing and to achieve high data input speeds. The technology has been tested and retested over the past 25 years and read-error rates of 1 in 10,000,000 are typical. It is less expensive than magnetic encodation or RFID chips. It's faster and more accurate than keyboard entry.