How do bar codes work?

[tbag]

I figure that at the store, when they get a new items in, they scan the bar code and program their registers to know that that bar code = Colgate Toothpaste, 12 oz.

But how is it that no two products ever show up with the same bar code? Is there some big organization that issues bar codes like Network Solutions issues web addresses?

What up?

Ted

[August West]

See the answer at How Stuff Works! (http://www.howstuffworks.com/upc.htm)