What is a Barcode? | Zebra

What is a Barcode?

Barcode label on box being scanned by a worker

A barcode is a pattern of variable-width bars and spaces which represents numeric or alphanumeric data in machine-readable form. The general format of a barcode symbol consists of a leading margin, start character, data or message character, check character (if any), stop character, and trailing margin. Within this framework, each recognizable symbology uses its own unique format.

What types of barcodes are there?

There are over thirty types of barcodes and the common ones include 1D Linear, 2D Data Matrix, 2D Quick Response (QR), and UPC Code.

Barcodes are divided into two main types: one dimensional (1D) and two-dimensional (2D).

1D barcodes are the oldest and most widely adopted of the two, are comprised of vertical lines and spaces that encode data in a machine-readable “font”. These barcodes are commonly used, but due to the encoding methodology, it takes more space to encode more data.

2D barcodes store information vertically and horizontally so more data can be encoded in a much smaller space for better error correction along with supporting much higher amounts of data. Barcodes can be further divided into symbologies, or barcode languages, which support different types and amounts of data.

1D Linear

Primary Purpose:

Reduce medication errors

Contains (minimum requirement):



Linear barcode required on nearly all drug products in the US

2D Data Matrix

Primary Purpose:

Identify and trace certain prescription drugs as they are distributed in the US

Contains (minimum requirement):

NDC, serial number, lot number and expiration date


2D data matrix required on the smallest saleable package

2D Quick Response (QR)

Primary Purpose:

Provide information (website nutrition information, etc.) about the product to which it is affixed

Contains (minimum requirement):

Not applicable


Not required by FDA on product labels and labeling


Primary Purpose:

Keep track of sales and inventory of retail products sold within the US and Canada

Contains (minimum requirement):

12-digit number that identifies the specific product


Required for OTC items

How do Barcodes work?

A barcode holds encoded information and a barcode scanner is able to translate this code into numbers and letters which is passed onto a host system.

Barcodes provide rapid, simple, and accurate readings, as well as data transmission for items that need to be identified, tracked or managed. Barcodes can be directly printed onto virtually any material and provide a cost-effective and accurate solution for capturing data. There is no single barcode type that has a universal business application. Therefore, a need for different symbologies exist.

When you breakdown a barcode, character sets are combinations of bars and spaces that represent a specific character. X Dimension is the width of the smallest bar or space element in the barcode which is also referred to as mil size (1mil = .001 inch). Quiet ones are the areas just before and after the barcode.

Components of a Barcode


There are different parts of a barcode, at the beginning of a barcode there is a number which is a system character and specific to an industry.  For example, zero is a grocery, and three is pharmaceutical. The price of a product itself is not encoded in the barcode, just the ability to look it up in the host system via the manufacturer and product code.

The barcode will contain a manufacturer code/company prefix which is from six to ten digits in length and is a globally unique prefix assigned to the company. This ensures that a product’s barcode is not confused with another company’s product.

The product code/item reference is a unique code assigned to the product and combines with the manufacturer code to make up the first eleven digits of the barcode.

A check digit is a special formula using those first eleven digits is used to calculate the check digit. This twelveth digit ensures the accuracy of the information in your barcode when it is scanned.

Characteristics of a barcode

What are the types of barcode scanners

There are three types of scanning technology, Laser Scanner, Linear Imager and Array Imager:

Laser Scanner

A laser scanner can read 1D printed barcodes but cannot read mobile barcodes. it is also unable to scan 2D codes or capture images but it does provide good performance on poor quality codes along with omni-directional scanning. These types of scanners tend to be a good and affordable option for standard, good quality 1D printed barcodes.

Linear Imager

A linear imager can reads 1D printed barcodes and 1D mobile barcodes but cannot scan 2D code nor is omni-directional. It also cannot capture images but does provide excellent performance on poor quality codes and high density codes.

Array Imager

An Array Imager can read 1D and 2D printed and mobile barcodes and most have the ability to capture images. They provide excellent performance on poor quality codes and high density codes along with omni-directional scanning. An Array Imager can also be optimized to support signature capture, OCR, direct part marks and document capture.