What are the Main Components of RFID?

In RFID(Radio-frequency identification) technology, the objects are tracked using special tags known as RFID tags. These tags carry information that is estimated to be about 2000 bytes. The main advantage of these tags is that they have a high throughput i.e. over hundreds of tags can be read at the same time. There are three main components of this technology: 

Scanning Antenna or Coil
The scanning antenna acts as a source for sending out a radio-frequency signal.
This signal provides a means of communication with the RFID tag. A scanning antenna can be of two types: the one that can be permanently affixed to the ground and the one that is available in a hand-held version. A new type of the antenna is recently introduced in which it is built into the door frame.

Transceiver
A transceiver with a decoder is used to interpret the information from the tags. When packaged with an antenna, it is also known as a reader or interrogator.
 Function of the reader is to decode the encoded data and then pass it to the host
computer.

Transponder
A transponder is the RFID tag that has been programmed to store certain information. Transponder can be of two types: Active and passive.
Active transponder has an internal battery and performs the basic operation of read/write, and passive transponders are those transponders that obtain their operating power from the reader. They don't need an external power source.