Far-field communication is
|“||[r]adio communication between an RFID reader and a tag that relies on electromagnetic wave radiation, rather than on inductive coupling between reader and tag.||”|
The far field signal decays as the square of the distance from the antenna, while the near field signal decays as the cube of distance from the antenna. So passive RFID systems that rely on far field communications have a longer read range than those that use near field communications.
- GS1 EPCglobal Glossary (full-text).