Bar codes, or Universal Product Code (UPC) symbols, adorn nearly everything we buy today. The codes include both numbers and a series of stripes that checkout scanners can read. But here's the key: the black and white stripes are nothing more than a simple code that is a machine-readable version of the number on the symbol.
The bars in a UPC symbol are similar to the dots and dashes of Morse code, only instead of decoding a string of sounds, scanners decode information stored in the widths of the alternating black and white stripes. Morse codes have two components - long dashes and short dots. UPC codes have three components; a thin line, a medium line that is twice as wide as the thin line, and a thick line that is three times as wide as the thin line.
In Morse code, each letter is represented by a specific string of sounds. Three dots represent the letter "s," for example, and three dashes represent the letter "o." Morse code for the familiar "SOS" message indicating a vessel in trouble is "dot-dot-dot dash-dash-dash dot-dot-dot."