Bar code
From WLCS
Technical Definition
A series of vertical bars of varying widths, in which each of the digits zero through nine are represented by a different pattern of bars that can be read by a laser scanner. The bars are commonly found on consumer products and are used especially for inventory control.[1]
Layman's Definition
The black and white lines found on products in a store are a barcode.
Examples
A products in Giant has a bar code in the back so that compiling the prices when someone is done shopping is easier.
Resources
[1]Answers.com, "bar code". Available at [1], Accessed march 6, 2009.