An EAN-8 is an EAN/UPC symbology barcode and is derived from the longer International Article Number (EAN-13) code. 

It was introduced for use on small packages where an EAN-13 barcode would be too large; for example on cigarettes, pencils, and chewing gum packets. 

It is encoded identically to the 12 digits of the UPC-A barcode, except that it has 4 (rather than 6) digits in each of the left and right halves. 

EAN-8 barcodes may be used to encode GTIN-8 (8-digit Global Trade Identification Numbers) which are product identifiers from the GS1 System. 

A GTIN-8 begins with a 2- or 3-digit GS1 prefix (which is assigned to each national GS1 authority) followed by a 5- or 4-digit item reference element depending on the length of the GS1 prefix), and a checksum digit.

EAN-8 codes are common throughout the world, and companies may also use them to encode RCN-8 (8-digit Restricted Circulation Numbers), and use them to identify own-brand products sold only in their stores. 

RCN-8 are a subset of GTIN-8 which begin with a first digit of 0 or 2.[2]

The International Article Number (also known as European Article Number or EAN) is a standard describing a barcode symbology and numbering system used in global trade to identify a specific retail product type, in a specific packaging configuration, from a specific manufacturer. The standard has been subsumed in the Global Trade Item Number standard from the GS1 organization; the same numbers can be referred to as GTINs and can be encoded in other barcode symbologies defined by GS1. 

EAN barcodes are used worldwide for lookup at retail point of sale, but can also be used as numbers for other purposes such as wholesale ordering or accounting.

The most commonly used EAN standard is the thirteen-digit EAN-13, a superset of the original 12-digit Universal Product Code (UPC-A) standard developed in 1970 by George J. Laurer.[1] 

An EAN-13 number includes a 3-digit GS1 prefix (indicating country of registration or special type of product). 

A prefix with a first digit of "0" indicates a 12-digit UPC-A code follows. 

A prefix with first two digits of "45" or "49" indicates a Japanese Article Number (JAN) follows.

The less commonly used 8-digit EAN-8 barcode was introduced for use on small packages, where EAN-13 would be too large. 

2-digit EAN-2 and 5-digit EAN-5 are supplemental barcodes, placed on the right-hand side of EAN-13 or UPC. 

These are generally used for periodicals like magazines[2] or books,[3] to indicate the current year's issue number; and weighed products like food, to indicate the manufacturer's suggested retail price.ABSA3132

Digits sense.

- 2 digits for the country code or system code

- 5 digits for the society identification

- 5 digits for the product identification

- 1 digit for the checksum

The Universal Product Code (UPC) (redundantly: UPC code) is a barcode symbology that is widely used in the United States, Canada, Europe, Australia, New Zealand, and other countries for tracking trade items in stores.

UPC (technically refers to UPC-A) consists of 12 numeric digits that are uniquely assigned to each trade item. 

Along with the related EAN barcode, the UPC is the barcode mainly used for scanning of trade items at the point of sale, per GS1 specifications. 

UPC data structures are a component of GTINs and follow the global GS1 specification, which is based on international standards. 

But some retailers (clothing, furniture) do not use the GS1 system (rather other barcode symbologies or article number systems). 

On the other hand, some retailers use the EAN/UPC barcode symbology, but without using a GTIN (for products sold in their own stores only).

Code 39 (also known as Alpha39, Code 3 of 9, Code 3/9, Type 39, USS Code 39, or USD-3) is a variable length, discrete barcode symbology.

The Code 39 specification defines 43 characters, consisting of uppercase letters (A through Z), numeric digits (0 through 9) and a number of special characters (-, ., $, /, +, %, and space). 

An additional character (denoted '*') is used for both start and stop delimiters. 

Each character is composed of nine elements: five bars and four spaces. 

Three of the nine elements in each character are wide (binary value 1), and six elements are narrow (binary value 0). 

The width ratio between narrow and wide is not critical, and may be chosen between 1:2 and 1:3.

The barcode itself does not contain a check digit (in contrast to—for instance—Code 128), but it can be considered self-checking on the grounds that a single erroneously interpreted bar cannot generate another valid character. 

Possibly the most serious drawback of Code 39 is its low data density: It requires more space to encode data in Code 39 than, for example, in Code 128. 

This means that very small goods cannot be labeled with a Code 39 based barcode. However, Code 39 is still used by some postal services (although the Universal Postal Union recommends using Code 128 in all cases[1]), and can be decoded with virtually any barcode reader. 

One advantage of Code 39 is that since there is no need to generate a check digit, it can easily be integrated into an existing printing system by adding a barcode font to the system or printer and then printing the raw data in that font.[2]

Code 39 was developed by Dr. David Allais and Ray Stevens of Intermec in 1974. Their original design included two wide bars and one wide space in each character, resulting in 40 possible characters. 

Setting aside one of these characters as a start and stop pattern left 39 characters, which was the origin of the name Code 39.[3] Four punctuation characters were later added, using no wide bars and three wide spaces, expanding the character set to 43 characters. 

Code 39 was later standardised as ANSI MH 10.8 M-1983 and MIL-STD-1189.[4] MIL-STD-1189 has been cancelled and replaced by ANSI/AIM BC1/1995, Uniform Symbology Specification