Barcodes are a set of little stripes that appears on the price tag of virtually every product on the market. At a glance, they appear to be entirely random, as if you could just draw some lines on a sheet of paper and no one would know the difference. In truth, however, each barcode has its own meaning encoded in its design that can be deciphered and processed by a machine. Originally, only devices built specifically for scanning barcodes could interpret them, but nowadays we have barcode scanning software, which is available for smart phones and desktop printers as well.
Barcodes were first created as a means to label railroad cars, but the practice proved commercially unsuccessful. It wasn't until they were incorporated by retailers that barcodes achieved widespread public use. Once they were brought into supermarkets to help automate checkouts, they quickly became standard for performing transactions, almost to the point of being universal.
Since then, they have been used for an assortment of other purposes that are usually referred to as automatic identification and data capture (AIDC). In 1974, a pack of chewing gum became the very first item to ever be scanned with the Universal Product Code, an early form of barcode that is now widely used in the United States and other countries. While the parallel line format is perhaps the most well-known, barcodes can take a variety of appearances; dots, rectangles and an assortment of other geometric patterns are all used in barcodes today.
Barcode readers come in a variety of forms. Although barcode scanning software is becoming more prevalent, devices made to interpret the codes are still used as well. These readers include a light source, a lens and a light sensor to translate optical impulses into electrical ones, which is important for interpreting the barcode's meaning. Almost all barcode readers also include special circuitry that allows them to analyze image data from the light sensor before sending the barcode's data to the output port of the scanner. Specific types of barcode readers include laser scanners, charge-coupled device (CCD) readers, camera-based imaging scanners, omni-directional scanners, and cell phone cameras. Barcode readers can also be hand-held or stationary, depending on how they're built.
Barcodes continue to be the most popular items used for processing transactions, and will likely continue to be for a long time. Of course, the time will probably come when there are more efficient ways of labeling products, but for now (especially with the advent of more advanced barcode scanning software), things are going rather smoothly as they are.