In the present paper a very brief introduction is provided to the theory of kinetic waves relevant to the description of wave heating in fusion machines and focussing mostly on radio frequency or ion cyclotron resonance frequency waves in tokamaks. The text starts by sketching the basic philosophy underlying the standardly adopted methods, describing the interaction of a single particle with a given wave and the assumptions typically made to arrive at a trustworthy description of the energy exchange, and ends by discussing some of the subtleties of the modeling of wave-particle interaction in inhomogeneous magnetized plasmas. None of the topics will be treated in full detail. Hence, by no means, this text is meant to be all-inclusive. Rather, it aims at providing a framework that should allow understanding what are the difficulties involved, leaving out the detailed derivation of the expressions as well as subtleties such as relativistic corrections. The interested reader is referred to the provided references - and the references given therein - for more in depth information.