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## Main Question or Discussion Point

Please teach me this:

I do not understand why we call functional integral procedure in QFT being ''quantization'' procedure.Because the integration is the ''summing up'' procedure,but not ''dividing'' into ''quantum'' procedure.Or does this term(quantization) has a origin of being able to deduce Feynman diagrams from functional integral formalism?By the way,does it in the nonperturbative QFT we still use Feynman diagrams?

Thank you very much for your kind helping.

I do not understand why we call functional integral procedure in QFT being ''quantization'' procedure.Because the integration is the ''summing up'' procedure,but not ''dividing'' into ''quantum'' procedure.Or does this term(quantization) has a origin of being able to deduce Feynman diagrams from functional integral formalism?By the way,does it in the nonperturbative QFT we still use Feynman diagrams?

Thank you very much for your kind helping.