Involves a chip with an antenna that when activated by a reader, can send or receive information.  It has several advantages over bar codes, foremost that it can be read with out a line of sight to an item, making it much easier to get automated reads and to do so in large quantities instead of one by one.  Placing a reader at the entrance to a distribution center, a stockroom, or even a trash compactor will make tracking goods easier and more automated.