Barcodes have become an essential technology in the automation of information institutions by playing the role of computerized accession numbers. It is a unique identifier that links a specific piece of information to its computer record. Barcoding technology has been in use for more than five decades. It began its use for commercial purposes in the United States. As it gradually gained popularity, barcodes also began to be used for other purposes. In 1972, libraries began using barcode technology. Gradually, barcode technology began to spread in libraries and information science institutions around the world.

We can see barcodes as a way of storing information in which the combination of vertical black lines (bars) of different widths and white spaces between them—these two—is stored. It is printed in a specific pattern that a barcode scanner can read. The scanner takes the signal from the lines and sends it to the computer, and the computer recovers the signal and displays it on the monitor. A barcode acts as a unique control number that provides relevant information about an item. The black text in a barcode represents 1, and the blank space represents 0. So a barcode is essentially a series of computer-readable ones and zeros that are used instead of numbers and letters. There are different types of barcodes, and most of them store information through different combinations of thick and thin bars.

Types of Barcodes:

There are over 40 types of barcodes. The complete set of character patterns that can be used for a particular type of barcode is called the symbology of that type. Each symbology has its advantages and disadvantages. Modern scanners can easily identify any symbology and decode its code. The three most widely used barcode types are:

Universal Product Code: This code is commonly used for retail sales. Its main advantage is standardization. Due to this, thousands of organizations all over the world can encode and decode the same data.
Code 39: Code 39 is followed for the introduction of a barcode system for general libraries. It can contain letters, numbers, and some special characters.
Interleaved 2 of 5: It can only encode numbers, so it has a lot of flexibility.

Barcode Techniques:

Two widely used techniques for barcoding are Smart Bar Code and Generic or Dumb Bar Coding.

1. Smart Bar Coding: Smart barcoding is a popular barcoding technology that is used all over the world. It is also called a customized bar code. This technology creates a smart bar codeby processing the bibliographic records stored in the library database. This item information (bibliographic information for each item) is linked to a unique number and printed on a barcode label containing all this information. It contains information about the shelf location of the item, author, title, publication date, edition, etc., and that unique identifier number. This technology will be more effective if the library’s overall bibliographic information is properly entered into the library database and the database maintenance is also updated; because then the occurrence of accidental barcode labels for items that are not in the library collection can be avoided.

2. Generic Barcoding: Generic barcodes are used instead of smart barcodes in libraries where the entire content update record is not included in the database or where the bibliographic record does not contain sufficient information about different content. Generic barcodes are commonly known as “dumb” barcodes. Generic barcodes have no intrinsic relationship to the information content; they simply consist of a barcode and a number that can be associated indiscriminately with any library item. Generic barcoding can be done in two ways:

Each item must be barcoded while connected to a computer terminal, then linked to the library system by matching the appropriate bibliographic record from that item, transferring the necessary information to the database, and then entering the barcode number.
You have to go to each shelf with the library shelf list, barcode each item along with the shelf list, then link that item from the shelf list to the computerized library system.The problem with this method is that all library collections must be brought to the computer for barcoding, or a two-step process must be completed to label and link.

However, according to many experts, a combination of smart and generic barcodes can ensure success in a code-barcoding project. It is more reasonable to use smart barcodes for books and generic barcodes for serials, multi-volume feature sets, reports, etc. In addition, it is more convenient to use generic barcodes to link user information.

Barcode Decoding Techniques:

Wand: It is shaped like a pencil and has a longer attached part at the end. The user has to take the wand in his hand and pass it over the barcode. The wand makes a slight sound while scanning. Although it is a cost-effective tool, it requires practice to master its use.
CCD scanner/charged couple device: The CCD scanner looks like the tip of a vacuum cleaner. It has to be held over the barcode for scanning. It works perfectly and does not require much skill or practice to use. However, its scanning range is short, and it does not work well at a distance of more than 3 inches.
Laser gun: It looks like a pistol. When the user holds it in his hand and pulls the trigger, a beam of light comes out of it and passes over the barcode. It is fast to use, has a long scanning range, and does not require much skill to operate. However, it is relatively expensive.
In-counter scanner: This scanner is placed on top of the ATM circulation counter, and the bar code is scanned over it. It is fairly accurate but expensive.
On-counter scanner: This is placed on top of the counter, but the scanning part is horizontal rather than vertical. It is also expensive and lacks flexibility in use.
Badge scanner: It looks like a small box with a slot in it. The user passes a card or badge with a barcode attached through this plate. It is not very expensive and does not require much effort to master its use.

Barcodes have transformed data management and tracking across various industries by providing efficiency, accuracy, and scalability. Different types, such as 1D and 2D barcodes, serve specific purposes, while advanced technologies like QR codes and RFID offer versatility in modern applications. As technology continues to evolve, barcoding remains essential for inventory management, retail operations, and automated systems, effectively bridging the gap between manual processes and digital transformation.