The barcode has become a ubiquitous tool for encoding data in a way that allows it to be retrieved easily by an electronic reader. However, what many people are unaware of is the number of manners in which the data can be encoded. These different methods for indexing information are called symbologies. Knowing the advantages of each format of data storage can help one choose which symbology is best suited to a specific application.
There are two main types of barcode symbology, each of which is divided into several smaller groups.
1. The first type is linear barcodes, which consists of barcodes like the UPC (Universal Product Code) and Codabar. These are so called because barcode scanners only have to scan the length of them, without taking the vertical dimension into account. Linear barcodes were the first variety used, and they have an extremely wide variety of applications. Typically, a linear barcode won’t actually contain the information being encoded. Instead, they contain enough information to retrieve the rest from a database.
Codabar Linear Barcode
Linear barcodes generally consist of a series of black lines of varying thickness, with numbers beneath them. These are used in many different industries, since they’re cheap and can typically contain all the necessary data for simple applications. There is an upper limit to the amount of information that can be stored using linear barcodes, however. Typically, as the quantity of information contained in a linear barcode increases, so does its physical width.
2. The second main type of symbology is the 2-D barcode, which includes symbologies like the Data Matrix, PDF417 and QR codes. Unlike the linear barcode, these contain information both vertically and horizontally. This means that one can store considerably more data than with linear barcodes, sometimes even obviating the need to retrieve the information from a database. In addition, they can usually store this information in a smaller area than a linear barcode could, which makes them useful for containing large amounts of data on small products. The technology required for reading these barcodes is newer, more expensive, and less wide-spread than that required for reading their linear counterparts. However, as time goes on and the cost of the technology goes down, 2-D barcodes are becoming more widely used.
2-D barcodes appear quite different from their linear counterparts. Instead of a series of black bars, they typically consist of a grid of black and white boxes. While 2-D barcodes have not yet replaced the linear barcode as the standard for retail, they have a growing application in advertising. Many modern phones have the capability to photograph and analyze these 2-D barcodes.
These two main groups of barcode types are further divided into a huge variety of subgroups, each of which has their own distinct benefits and disadvantages. Knowing what characteristics one needs in a barcode can help one choose the symbology that best fits those needs.