What's in a UPC symbol?

I thought this was interesting...a breakdown of a standard UPC barcode that we all know so well.

Left Hand Guard Bars - These bars serve as a starting reference point for the scanning devices.

Number System Character - This digit identifies the type of manufacturer or how the bar code will be used. For example 0, 6, and 7 are generally used in the retail industry, while 3 is assigned to the health and drug manufacturing industries.

Number System Bars - These bars correspond to the Number System Character.

Manufacturer ID Number - Each company must apply for a Universal Product Identification Number with the Uniform Code Council. The UCC assigns each company a unique six digit identification number for use on all of their products. The number is composed of the Number System Character and a five digit manufacturer's code.

Manufacturer ID Bars - These bars correspond to the Manufacturer's ID Number.

Tall Center Bar - These bars serve as a middle reference point for the scanning devices.

Item Number - Each company is responsible for assigning a unique five digit number to each of their products.

Item Bars - These bars correspond to the Item Number.

Modulo Check Character - This digit is derived from a mathematical formula based on the unique set of numbers in each bar code that helps ensure the accuracy of the data scan.

Modulo Check Bars - These bars correspond to the Modulo Check Character.

Right Hand Guard Bars - These bars serve as an ending reference point for the scanning devices.

I found this information at this website.