UPC (Universal Product Code) is the most popular and most frequently used of all bar codes. Its most common application is in the grocery industry and price product. UPC is designed to match the number of the product with information such as the manufacturer, product, and price. UPC codes are administered by the Uniform Code Council in Dayton, Ohio. This organization controls specifications for all UPC, to ensure that the strict guide-lines are met.

       UPC is a fixed-length, numeric-only code. Two versions that are the most commonly used today are UPC version A, which has twelve digits; and UPC version E, which has six digits. UPC-E is popular for applications in which space is limited for the placement of the code.

       UPC is well suited for grocery applications. It provides a high read rate even as the product moves rapidly past the scanner. Some other considerations for the scan ability of UPC lie in the fact that the codes must be on products that are to be frozen, wet, or shrink wrapped, etc.

       EAN (European Article Numbering) is the European counter-part of the UPC. EAN is also a fixed length code that is numeric only. The two popular versions are EAN-8, which has eight digits, and EAN-13, with thirteen digits. Like UPC, the EAN start and stop bars are longer than the character bars.