Once a manufacturer applies for a standardized barcode, and it is approved by the Uniform Code Council (UCC), he is issued a 12-digit Universal Product Code (UPC). This code does all the classifications for the acquisition of a product. Every different size of the same product has a different UPC. It is among the most widely used barcode systems in the world. Seeing it on your everyday items probably would have gotten you to think, ‘hey, maybe I can read these barcodes myself? ‘ Well you are right, you can read them yourself, without a standard reader.
Source code is a listing of the instructions that make up the ‘recipe’ for a software package. Software engineers write source code in a programming language (like C++ or FORTRAN) that a human can both read and understand, as well as fix and modify. Most commercial software is released in machine language or what are called ‘binaries’-a long string of ones and zeroes that a computer can read and execute. However, a human cannot read. The source code is basically the recipe for the binaries; and if you get the source code, you can understand what the author was attempting to accomplish when she wrote the program-which means you can change it. If you have just the binaries, you typically cannot either understand or modify them. Therefore, shipping binary code is very effective way for proprietary software companies to control what you can perform with the software you buy.
The 12-digit barcode that we use is the standard UPC-A. These codes can be of different types, based on different systems.
These lines are of varying thicknesses, and are numbered in an ascending order according to the growing thickness.
Now, take opinion of the sequence of lines exactly in the midst of the code. The middle bars are an alternating sequence of ‘white-black-white-black-white’. This makes the code ’01010′.
The rest of the bars each contain their own number codes. Each code represents a particular bit of information about the product.
Now, look at all the numbers at the bottom. Every number is associated with a group of a 4-line set. These numbers are again given a clear set of number codes (given below).
The first 6 digits contain information about the purchase of the subject and the manufacturer information. The latter 5 digits describe that particular item in detail, like the product size, version, etc. The last digit is called the ‘check digit ‘, and is used by the UPC scanner for error detection.