Barcode Glossary: 40 Terms To Know About Barcodes

Barcode Glossary: 40 Terms To Know About Barcodes

Barcode Basics | 6 May 2019

Posted by Lisa Sarvie

Barcode Glossary

Finding a barcode solution that works for you and your company doesn’t have to be difficult, even if you don’t know much about barcodes! As a company that has been trusted to provide quality barcode labels since 1975 we sure know a lot about them, and hope we can help you make an educated decision for your company. In this post we have defined 40 terms we believe will be helpful in your journey to finding the right barcode identification solution for you.



Short for one dimensional. One dimensional barcodes are represented by bars and spaces in a linear arrangement and are also called linear barcodes.


Short for two dimensional. Two dimensional barcodes are represented by black squares and spaces arranged along a vertical and horizontal axis.

Learn more about what makes linear and 2d barcodes different



Accuracy refers to the size of bars and spaces. Since the size of the bars in relation to each other represents data, an incorrectly sized bar could affect the accuracy of the read.


An alphanumeric barcode contains characters that are representative of numbers, letters and punctuation marks.



The dark colored rectangles and lines within a barcode are referred to as bars



Barcodes are a technology that use black rectangular shapes and white spaces to encode data. The encoded data is able to be read by a scanner and translated by a decoder.




A barcode that can be read successfully from either a horizontal or vertical scanning direction can be considered bidirectional.



Characters are represented as groups of bars and spaces. Characters represented in a barcode can be either numeric or alphanumeric.

Check Character

A character within a barcode that serves the purpose of mathematically checking the accuracy of the encoded data.

Clear Area

Also known as the quiet zone, the clear area is a space at the end of each barcode that must remain blank or the accuracy and readability of the barcode can be compromised.


The acronym for characters per inch. CPI is commonly used to measure barcodes.


Data Matrix Code

A type of 2d barcode.

Data Matrix Code


A device that takes the information stored in the barcode from the reader and translates it into a human readable form.


Dots per inch. A printing term referring to print resolution in the form of dots of ink per inch. Barcodes require a relatively high DPI to be read accurately.



The spaces and bars that make up a barcode.



A barcode that stands perpendicular to the horizon and is read horizontally. These are also called picket fence barcodes.



Another name for a vertical barcode, a bar code that is oriented paralled to the horizon. These are referred to as ladder barcodes, because due to their orientation the bars on the code can be compared to the rungs of a ladder.


Another name for a 1D barcode, a barcode that is represented using dark rectangular bars and spaces.

Linear Barcode

Take our crash course on linear barcodes



When the information procured by the reader differs from the data encoded within the barcode it read.


The width of the narrowest bar within a barcode.


Narrow Bar

The narrowest bar in a barcode. This term may also refer to the width of the narrowest bar in which case it becomes interchangeable with module.

Narrow Bar


An instance when no data can be obtained by the reader upon scanning. This usually only occurs in cases of error, be it operator error, a defective code or a failing scanner.


A barcode containing only characters representative of numbers.


Optical Throw

The shortest distance a reader can be from a barcode and still obtain data.


The way the barcode is aligned in reference to the horizon. In a linear barcode this can be horizontal or vertical AKA picket fence or ladder.


The required number of start, stop and check characters in a symbol. A symbol that requires a start, stop and check character will have three overhead characters, meaning if four characters are to be encoded with these overhead requirements, a total of seven characters would need to be printed.


Picket Fence

This term is synonymous with horizontal, referring to a barcode oriented perpendicular to the horizon with the bars standing upright like a picket fence.


QR Code

QR is short for quick response and refers to a type of 2D barcode used in several industries to improve data sharing. The data sharing aspect has been used by companies to promote marketing in addition to its intended internal uses.

QR code on mobile display

Quiet Zone

Another term used to refer to the clear area. The space on either end of a barcode that must remain blank in order for the code to be accurately read by the scanner.

Quiet Zone



Sometimes called a scanner, a reader is a device used to read barcodes. The reader takes in the optical information represented by the barcode and converts it into computer readable electrical signals.


How easily the barcode can be read by the reader. The readability can be affected by things such as the contrast between the bars and the background, an insufficient quiet zone or printing errors.



Also called a reader, a scanner is a device used to read barcodes. It works by taking in the optical information represented in the barcode and converting it into electrical signals that are readable to a computer.

Sequence Management Services

Software systems designed to ensure no duplicate barcodes are printed by tracking past barcode orders and sequence numbers.

Find more details about sequence management services on our blog

Start-Stop Character

Characters located on either end of a barcode indicating where the reader should begin reading and stop reading.

Start-Stop Character


The lighter colored elements of a barcode, located between bars and in the background.


The combination of all barcode elements: bars, spaces, background and quiet zones, into a single barcode.

Symbol Length

The total length of a barcode including quiet zones.


There are many different types of barcodes, each different type is referred to as a symbology. As an example, a QR code is a specific symbology of 2D barcode.



The term vertical barcode refers to a barcode that is oriented perpendicular to the horizon. This type of barcode is often referred to as a ladder barcode.

Vertical Barcode



Another name for the narrow bar, the narrowest bar within a barcode.

Since barcodes are everywhere their importance is often undermined, but it’s no coincidence they’re being used by companies all over the world. Companies of all kinds need practical tracking and identification solutions, and barcodes are currently the standard. We hope this glossary helps you to make a better educated decision during your barcode solution search.


Palmer, Roger C. The Barcode Book. 4th ed., Helmers Publishing, 2001, pp. 437-44.

The Little Book of Barcodes Download

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Lisa Sarvie

Lisa Sarvie is the Director of Customer Excellence here at Computype. From St Paul, MN, she works very closely with customers to ensure a positive experience. Lisa’s team works to ensure the customer experience with Computype is consistently satisfactory. Additionally, her team manages customer accounts to ensure all needs and specifications are consistently met.