A barcode is a series of dark lines and white spaces with varying widths that contains information about the product or object on which it is affixed. The lines or patterns within a barcode are a representation of alphanumeric characters with basic information about the product. The barcode is read by a barcode scanner which decodes the information within the barcode and converts it to digital characters which are then transmitted into the computer system.

Barcode technology has made it possible to collect and record data much faster, reduce human errors, and better manage assets and inventory. For these reasons, barcode has found many applications in various sectors such as retail, healthcare, warehousing, manufacturing, transport, and logistics.

Let’s dive deeper and learn more about barcodes.

Structure of a Barcode

  1. Quiet Zone (Margin)

The Quiet zone of a barcode is the blank space on either side of the barcode. It defines where the barcode starts and where it ends and prevents the scanner from picking up symbols that are not part of the barcode.  If the quiet zones are not wide enough, the scanner may not be able to read the barcode.

  1. Start and Stop Character

The start and stop characters depict the start and the end of data respectively within a barcode. These characters will vary depending on the type of barcode.

  1. Data (Message)

This refers to bar patterns that represent the data, which could be in form of numerical characters, alphabets, or alphanumeric. They are usually arranged from the left.

  1. Check Digit

The check digit is used to check whether the barcode data is correct. It is usually located immediately after the data (Message).

  1. Barcode Length

The barcode length is the total length of the barcode including the right and the left quiet zones. If the barcode length exceeds the width of the scanner, it becomes impossible to scan the barcode.


Types of barcode

Generally, there are two types of barcodes 1D and 2D barcodes.

ID Barcodes

They are also known as linear barcodes. 1D barcodes are the most commonly used barcodes especially in the retail sector where they are used on consumer goods. 1D barcodes appear as dark lines and white spaces with varying widths.

In 1D barcodes, the length of the barcode is determined by the number of characters within the barcode. The higher the number of characters, the longer the barcode. ID barcodes, therefore, tend to be limited in terms of the characters they can hold otherwise they would be too long. ID barcodes can only be read by a scanner from one direction, mostly in a horizontal position.

In the retail sector, 1D barcodes are used as unique product IDs. They are used to identify products that have other associated information that may change frequently. For instance, the prices of commodities are always changing but the barcode characters usually remain the same. The price of the product is usually not encoded in the barcode, instead, the barcode is used to identify a product in the products’ database.

2D Barcodes

2D barcodes use patterns such as squares, dots, and other symbols to encode data. Compared to the 1D barcode which holds a maximum of 20 characters, the 2D barcode can hold up to 4000 characters. 2D barcodes encode data in both vertical and horizontal which means that the barcode can be scanned from whichever direction.

2D barcodes can contain a variety of information in form of links, images, and voice. In terms of scanning, 2D barcodes can only be read by a scanner with 2D capabilities. This means that a 1D scanner will not read a 2D scanner however, a 2D scanner can read both 1D and 2D barcodes. One major advantage of the 2D barcode is that its structure contains enough information that enables it to decode even the partially damaged or defaced barcodes.

2D barcodes have a high data density which makes it possible to use on very small items where 1D barcodes would be problematic. They are also used in websites, healthcare, transport, logistics, and many other sectors.

In summary, understanding the basics of barcodes and the technology behind them enables us to appreciate this great invention. Over the years, barcodes have revolutionized business processes making them more productive and more efficient.