How does RFID technology?

 A radio frequency identification system consists of three parts:

A scanning antenna
A decoder to interpret the data transceiver
Answers - RFID tags - have been programmed information.
Scanning the radio antenna made in a relatively short range of low frequency signals. RF radiation do two things:
Providing the transponders (RFID) and communication tools
Provide RFID tag to communicate with the energy (in the case of passive RFID tag).
This is an absolutely essential part of the technology, RFID tags have no batteries needed, because time can be stored for long time may be used (probably 20 years).
Scanning antennas can be incorporated permanently into the surface of the handheld antenna is also available. It may take any form you need, for example, can be built into a door frame to accept people or objects through the data.

When the field with the RFID tag instead of scanning the antenna, it detects the signal from the antenna to activate. This "awakening" and the RFID chip data transmission, scanning the antenna load.

In addition, the RFID tag can be of two types. Active RFID tag has its own resources, labels benefit from this is that readers can still get more signal. Although this device is built around 10 years of life, limited life expectancy. Passive RFID tags, but does not require batteries and can be smaller and have an almost unlimited life.

RFID tags can be read cases, the technology for reading bar codes or optical for many.

Seal does not require the surface (and so was not easy and keausan)
Reading time is under 100 milidetik
A large number of tags read at once, not one by one.
In essence, this is RFID.