Ok. The UPC (American Barcode and really Universal Product Code) is a barcode symbology (i.e., a specific type of barcode), that is widely used in the United States and Canada for tracking trade items in stores.The UPC encodes 12 decimal digits as SLLLLLLMRRRRRRE, where S (start) and E (end) are the bit pattern 101, M (middle) is the bit pattern 01010 (called guard bars), and each L (left) and R (right) are digits, each one represented by a seven-bit code. This is a total of 95 bits. The bit pattern for each numeral is designed to be as little like the others as possible, and to have no more than four 1s or 0s in order. The shape is a rectangle.
The EAN (European Barcode or really European Article Number) is a barcoding standard which is a superset of the original 12-digit Universal Product Code (UPC) system developed in North America. As you see, North America adopted this barcoding system, but the UPC is mostly used. The first three digits of the barcode of any product represents the country. The EAN-13 barcode is defined by the standards organisation GS1.
The EAN-13 barcodes are used worldwide for marking retail goods. The less commonly used EAN-8 barcodes are used also for marking retail goods; however, they are usually reserved for smaller items, for example confectionery. In EAN-13 the symbol encodes 13 numerals divided into four parts:
* System code, the first two or three digits, usually identifying the country in which the manufacturer is registered (not necessarily where the product is actually made). When the EAN-13 barcode is a conversion of a 10-digit ISBN or ISMN code, the system code will be 978 or 979 respectively, or 977 for ISSNs.
* Manufacturer code, consisting of four, five or six digits depending on the length of the system or country code.
* Product code, consisting of five digits.
* Check digit, a single checksum digit. The check digit is computed modulo 10, where the weights in the checksum calculation alternate 1 and 3. In particular, since the weights are relatively prime to 10 the EAN system will detect all single digit errors. But since the difference of consecutive weights is even, the EAN system does not detect all adjacent transposition errors.
Note that EAN codes beginning with 0 are rarely used, as this is just an addition to a 12-digit UPC. Since most scanners and registers worldwide can read both equally, most manufacturers in North America still only use UPC. This size is a rectangle.
Hope I helped!