The document provides an overview of bar code technology and its uses and benefits. It discusses how bar codes work by encoding data in varying widths of black and white bars that can be scanned electronically. Bar codes allow for fast, accurate, and efficient data entry. The document outlines common applications of bar codes in retail, warehouses, healthcare, transportation and more. It also discusses the components needed for a bar code system and provides an example of how bar codes have improved operations at a library by streamlining check-in/check-out processes.