Question

what is quantum field theory​

Answer 1

ans:

Instead, what we interpret as "matter" is itself a quantum field. And these quantum fields, themselves, are made up of particles. The electromagnetic field? Made of particles called photons.

Answer 2

Answer:

Quantum Field Theory (QFT) is the mathematical and conceptual framework for contemporary elementary particle physics. In a rather informal sense QFT is the extension of quantum mechanics (QM), dealing with particles, over to fields, i.e. systems with an infinite number of degrees of freedom.