A barcode is a machine-readable pattern of bars or squares that encodes a number or text, most often a product identifier. When a scanner reads it, the point-of-sale or inventory system looks up the matching product, price and stock record instantly.
One-dimensional barcodes, the familiar lines, are read by a laser or camera scanner and are common on packaged retail goods. Two-dimensional codes, such as QR codes, store more data in a square pattern and can be read by cameras, including those in phones. Retail products typically carry a global trade item number printed as an EAN or UPC barcode, which suppliers register so the same code works across different retailers.
Retailers scan barcodes at checkout, when receiving deliveries, during stocktakes and when transferring stock between stores. Hospitality venues use them for packaged items and receiving. Businesses can also print their own internal barcodes for products that do not arrive pre-labelled, linking each one to a SKU.
Things to consider include print quality, label placement and scanner suitability. Damaged, faded or curved labels fail to read, and low-quality printers or poor contrast cause slow scanning. Make sure each barcode maps to exactly one product record, and remember that a barcode identifies a product type, not an individual item, which is a key difference from RFID.
Barcodes matter because they remove manual keying, speed up service and keep inventory data accurate. They remain the foundation of most retail systems, and newer technologies usually build on the same product identifiers.