What Are Barcodes and How Do They Work?

You likely see barcodes every day, whether shopping at the store or glancing at products you currently own. At the most basic level, barcodes are labels used for items, electronic forms and reports to make product management easy.

A barcode is a machine-readable graphic symbol consisting of vertical, parallel lines and spaces of varying widths. These vertical lines correspond to a series of numbers that encode information that can be used for an array of purposes.

Most barcodes are used to identify a product at point-of-sale, but not all. Many barcodes are also found on invoices, labels and shipping forms to aid in inventory tracking and theft management. Others encode information for coupons, mobile payments and more.

Types of Barcodes

In the big picture, most barcodes have similar traits: the barcode symbol (the vertical lines), the quiet zone (the white space before and after the vertical lines) and the digits, which are preceded by the “start character” and finished by the “stop character.” However, while the various barcode types look similar to the untrained eye, they’re quite different and serve different purposes.

Universal Product Code (UPC)

The standard barcode used by nearly all companies to identify products is the UPC. This type of barcode

consists of 12-digits, sometimes referred to as a GTIN-12 and is located on virtually every consumer product on the market.

European Article Number (EAN)

EAN codes, also called GTIN-13 or EAN-13, consist of 13 digits used throughout Europe to identify products. The primary difference between UPC and EAN is the placement of the numbers and the EAN country code designated by the first three digits.

Global Trade Item Number (GTIN)

GTIN is a term that refers to data structures within barcodes. For example, UPCs primarily use GTIN-12, and EAN codes use GTIN-13 codes. Essentially, GTINs are a global version of UPC or EAN with zeros appended by a company to identify its trade items.

Code 39 Barcodes

Code 39 barcodes (as well as Code 128, as seen below) can encode alphanumeric data, which allows them to be used in many different applications. Originally able to handle 39 characters (which gave the barcode its name), it now can handle 43 characters, including numbers, letters and some symbols. Code 39 barcodes are commonly used for inventory purposes in the automotive and electronics fields, among others.

Code 128 Barcodes

A Code 128 barcode, when compared to a Code 39, is much denser, with more vertical lines (known as bars) and less white space between the bars. Code 128 gets its name because it can represent all 128 ASCII code characters (which includes numbers, both upper- and lower-case letters, symbols and control codes). Because of that, it is considered a computer-friendly barcode. It is commonly used in the apparel, food, pharma and medical equipment industries in North America, Australia, New Zealand and some countries in Europe.

2D Barcodes

A newer variety of barcodes have layers of bars, spaces and dots in a square or rectangular box instead of vertical lines. The most well-known 2D barcode is the Quick Response (QR) code. These barcodes require a specialized scanner to read them, and they tend to hold far more information than a standard barcode.

How Do Barcodes Work?

Barcode software, such as MarkMagic, is needed to create the machine-readable code and print it onto the product packaging. A specialized piece of hardware called an optical scanner is required to read a barcode. When a barcode is scanned, the device converts the lines and spaces into a data signal decoded into alphanumeric characters. This data is then read and integrated into your company’s database.

Barcodes and Labels With CYBRA

Barcodes are essential for retailers, warehouses and distributors who sell products around the globe. Luckily, innovative barcode software is automating this process so that you save time and money.

MarkMagic is fully embedded in the most popular WMS packages and designed to run on virtually every operating system, including IBM AIX, Windows, Mac OS, Linux, Unix, as well as a cloud-based version. Speak with our barcoding experts today to see how we can help you.

Chris Capelle is a technology expert, writer and instructor. For over 25 years, he has worked in the publishing, advertising and consumer products industries.


Investopedia – Barcode


Barcode-Us – UPC Barcodes: The Basics

GS1 – EAN/UPC barcodes

ASCII Code – ASCII Code – The extended ASCII table

Computype – Linear vs. 2D Barcodes in the Lab: What’s The Difference?


Barcode Labeling Software

RFID Tracking Software

Barcode Labeling Software

RFID Tracking Software


[Case Study]

How Roth Industries Package Thousands of Prepared Food Products Every Week.


2022 RFID Integration Guide - Learn how to turn your RFID tags into a great investment


How You Can Benefit from Digitizing Your Shipping Forms and Labels with MarkMagic

[Case Study]

How Roth Industries Package Thousands of Prepared Food Products Every Week.


2021 RFID Integration Guide - Learn how to turn your RFID tags into a great investment


How You Can Benefit from Digitizing Your Shipping Forms and Labels with MarkMagic


CYBRA Headquarters
CYBRA HQ (Yonkers, NY)


Over 30 years of software sales & development. Thousands of customers worldwide. And, we’re just getting started. CYBRA specializes in RFID tracking technology and barcode forms & labeling software solutions. Learn More