Barcodes, comprised of colored bars in various widths and white spaces, create a specific pattern that represents a group of characters. Barcode readers rely on photoelectric sensors and electrical signals to decipher the pattern by measuring each bar and space.
Retail and manufacturing companies, along with government, military and research agencies use barcodes to manage inventory, store data and track items. To manage inventory, retailers and manufacturers assign a barcode to both the physical item and to the recorded description in inventory databases. After the barcode reader deciphers the barcode, the information is sent to a computer which searches the database to find a match. This technology is also used in retail stores to make purchasing easier and faster as barcodes include the prices of goods.
In addition to helping maintain accurate inventory control, barcodes are also used to store and retrieve data. For example, 2-D barcodes may provide additional product information or links to websites that feature similar products. These barcodes may be placed on item containers or in print advertising as most smart phones have photoelectric sensors. Researchers and scientists may use barcodes for tracking migratory habits of animals and other wildlife or to distinguish between research subjects. Shipping companies use barcodes to track packages, while hospitals use barcodes to identify patients.