An RFID tagging system usually includes the tag itself, a read/write device, and a host system application for data collection, processing, and transmission. An RFID tag (sometimes called an RFID transponder) consists of a chip , some memory and an antenna .
RFID tags that contain their own power source are known as active tags. Those without a power source are known as passive tags. A passive tag is briefly activated by the radio frequency ( RF ) scan of the reader. The electrical current is small -- generally just enough for transmission of an ID number. Active tags have more memory and can be read at greater ranges.
Increasingly, RFID tagging is used in hotel door locks. Although more expensive to use than the traditional physical key locks or magnetic card locks, RFID tags provide weatherproof capability and better tracking.('What to know more about the advantages of RFID key card locks?')