For RFID systems to work the following components are essential:
Tag (Passive or active)
Reader (Handheld, Fixed or Integrated)
Software (also known as middleware)
Information is sent and read from RFID tags by a reader using radio waves.
In passive systems, which are the most common, RFID reader transmits an energy field that “wakes up” the tag and provides the power for the tag to respond to the reader. In active systems, a battery in the tag is used to boost the effective operating range of the tag and to support additional features over passive tags, such as temperature sensing. Data collected from tags is then passed through communication interfaces (cable or wireless) to host computer systems in the same manner that data scanned from bar code labels is captured and passed to computer systems for interpretation, storage, and action.