Technical Jargon of NFC

 NFC-based communication between two devices is possible when one device acts as a reader/writer and the other as a tag.

• The tag is a thin simple device containing antenna and small amount of memory. It is a passive device, powered by magnetic field. Depending on the tag type the memory can be read only, re-writable, and writable once.

• The reader is an active device, which generates radio signals to communicate with the tags. The reader powers the passive device in case of passive mode of communication

     Source : www.touchwork.com