A barcode is an optical machine-readable representation of data, which shows data about the object to which it attaches. Originally barcodes represented data by varying the widths and spacing of parallel lines, and may be referred to as linear or one-dimensional (1D). Later they evolved into rectangle, dots, hexagons and other geometric patterns in two dimensions (2D). Although 2D systems use a variety of symbols, they are generally referred to as barcodes as well. Barcodes originally were scanned by special optical scanner called barcode readers later, scanners and interpretive software became available on devices including desktop printers and smart phones.The first use of barcodes was to label railroad cars, but they were not commercially successful until they were used to automate supermarket checkout systems, a task for which they have become almost universal. Their use has spread to many other tasks that are generically referred to as automatic identification and data capture (AIDC).
A barcode system is a network of hardware and software, consisting primarily of mobile computers, printers, handled scanner, infrastructure, and supporting software. Barcode systems are used to automate data collection where hand recording is neither timely or cost effective. Bar coding systems are not radio-frequency identification (RFID) systems even though the companies that provide barcode equipment will often also provide RFID equipment and many companies use both technologies as part of larger resource management systems.
