Wireless Radio Frequency Identification, or RFID, is a type of automatic identification tech that uses radio waves for two-way data exchange without touching. It reads and writes data on tags, or smart cards, to identify objects and transfer info. This is seen as one of the biggest trends in information tech in the 21st century. 
RFID tech works by zapping radio waves for fast data swapping and storage. It hooks up with a database system through wireless communication and data-access tech, achieving two-way communication to identify things. It's used for data swapping, tying together an intricate system. In this system, tags are read using electromagnetic waves. Depending on the distance, it's divided into nearfield and farfield. The data exchange method between readers/writers and tags also matches this, being either load modulation or backscatter modulation.