RFID or Radio Frequency Identification is a constantly evolving technology that has made its foray into our lives from the inner circles of science very rapidly. It is basically one of the automatic identification systems like bar codes, smart cards, etc. which helps in identification of objects. However, because of its advanced and user friendly features RFID scores an edge above these antiquated technologies.

RFID system consists of specially designed RFID tags, readers, edge servers, middleware, and application software. The system works by transmitting the data stored in the tags to a RFID reader that in turn reads it and processes the data according to the application's specifications. This transmitted data can possess information about the location of the tag, or specifics concerning the product tagged. The system also includes an interrogator, which has a certain range in which it detects the RFID tag, activates it, and receives the response.

RFID tags, which are being used for a variety of purposes across different sectors, are primarily of three types. These three types are- passive, semi-passive or semi-active and active tags. This classification is based on the source of power supply in the RFID tags. The passive RFID tags do not have a power supply of their own. They make use of the electrical current induced by the radio frequency signal to transmit their response. Thus, despite of having no internal power supply these tags don't require batteries. These tags are small in size and have a range extending from 2mm to few meters. Moreover, they are the cheapest among the three varieties and thus, most widely used. The semi-passive or semi-active RFID tags have a small battery inside. Hence, they are a bit faster in responding and collating data than the passive tags. Besides this, their size and range are quite similar to the passive tags. The active tags have their own internal power source. Thus, they are bigger in size and possess a larger memory size with the ability to communicate with their readers even with large distances between them. However, they are the most expensive of all the three variants. Hence, so far their usage is quite limited.

The basic function of RFID reader is to communicate with the RFID tag by emitting radio waves through its antenna. The RFID readers are classified on the basis of their range like UHF, HF (13.56 MHz) and microwave (2.45 GHz). Their range also governs the prices of these readers. Hence, the UHF readers are the costliest and their prices range anywhere from $2500 to $3000. The reason why these readers are so expensive is because there is no IC integration and also because of its low volume of production and the non-availability of customized components. However, according to a new prediction by a research company, the prices of UHF readers are bound to fall by the end of 2006 or in 2007. This is because as more and more vendors will invest into this technology and as the demand levels will increase the component prices will fall.

Thus, RFID is a technology that has a bright future and is capable of benefiting the mankind.