Radio-frequency identification(RFID) is the use of a wireless non-contact system that uses radio-frequency electromagnetic fieldsto transfer data from a tag attached to an object, to an RFID reader nearby for the purposes of automatic identification and tracking.

The RFID tag can be affixed to an object and used to track and manage inventory, assets, people, etc. For example, it can be affixed to cars, computer equipment, books, mobile phones, etc.  The tag can be read if passed near a reader, even if it is covered by the object or not visible. The tag can be read inside a case, carton, box or other container, and unlike barcodes RFID tags can be read hundreds at a time. Bar codes can only be read one at a time.

The RFID tag includes a small RF transmitter and receiver. Since tags have individual serial numbers, the RFID system design can discriminate several tags that might be within the range of the RFID reader and read them simultaneously.

A typical RFID chip is capable of carrying more or less 2,000 bytes of data and works up to a distance of 20 feet for high-frequency scanners.

The basic but critical elements of an RFID system include tags, printer, reader, sensors, middleware (for data-filtering and data-flow management), and, if needed, some software adaptations to enable legacy applications and systems to receive RFID-generated data.

The key advantages of RFID are:

1. No line of sight required.
2. Able to be read even in the harshest environments.
3. Long read range.
4. Portable database.
5. Multiple tag read/write.
6. Ability to track items, equipment and even people in real-time.