Quantum Field Theory is another step in the developement of physics. After quantizate matter (athomic theory) and energy (quantum theory), QFT quatizates fields.
The classical concept of field as an force that acts at distance disappears. In QFT all forces (except gravitation) appears as the result of interchanging virtual particles (for example, electromagnetism is the result of photons interchanging), that transport energy and moment from one particle to another.