Barcodes:

A barcode (also bar code) is an optical machine-readable representation of data. Originally, bar codes represented data in the widths (lines) and the spacings of parallel lines, and may be referred to as linear or 1D (1 dimensional) barcodes or symbologies. They also come in patterns of squares, dots, hexagons and other geometric patterns within images termed 2D (2 dimensional) matrix codes or symbologies. Although 2D systems use symbols other than bars, they are generally referred to as barcodes as well.
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 in which they have become almost universal. Their use has spread to many other roles as well, tasks that are generically referred to as Auto ID Data Capture (AIDC). It costs about US$0.005 to implement a barcode compared to passive RFID which still costs about US$0.07 to US$0.30 per tag.
Barcodes can be read by optical scanners called barcode readers, or scanned from an image by special software. In Japan, most mobile phones have built-in scanning software for 2D codes, and similar software is becoming available on smartphone platforms.
In point-of-sale management, the use of barcodes can provide very detailed up-to-date information on key aspects of the business, enabling decisions to be made much more quickly and with more confidence. For example:
• Fast-selling items can be identified quickly and automatically reordered to meet consumer demand,
• Slow-selling items can be identified, preventing a build-up of unwanted stock,
• The effects of repositioning a given product within a store can be monitored, allowing fast-moving more profitable items to occupy the best space,
• Historical data can be used to predict seasonal fluctuations very accurately.
• Items may be repriced on the shelf to reflect both sale prices and price increases.
Besides sales and inventory tracking, barcodes are very useful in shipping/receiving/tracking.
• When a manufacturer packs a box with any given item, a Unique Identifying Number (UID) can be assigned to the box.
• A relational database can be created to relate the UID to relevant information about the box; such as order number, items packed, qty packed, final destination, etc…
• The information can be transmitted through a communication system such as Electronic Data Interchange (EDI) so the retailer has the information about a shipment before it arrives.
• Tracking results when shipments are sent to a Distribution Center (DC) before being forwarded to the final destination.
• When the shipment gets to the final destination, the UID gets scanned, and the store knows where the order came from, what's inside the box, and how much to pay the manufacturer.
The reason bar codes are business-friendly is that bar code scanners are relatively low cost and extremely accurate compared to key-entry– only about 1 substitution error in 15,000 to 36 trillion characters entered.