2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41332QCD nonrelativistic effective field theories (NREFT) are the modern and most suitable frame to describe heavy quarkonium properties. In this talk I summarize few relevant concepts and some interesting physical applications of NREFT.9 pages, revtex4 style, Invited talk given at the "Workshop on Charmonium Spectroscopy: Past and Future", Genova, June 2001, to appear in the proceedings of the workshopHigh Energy Physics - Phenomenologytext