Energy deposition and heating during laser processing of materials are a consequence of the balance between the deposited energy, governed by optical parameters of the surface and characteristics of the laser radiation, and the heat diffusion, determined by thermophysical parameters and the interaction time. The kinetics of laser-induced plasma with maximum values of absorptance is described giving indication that maximum efficiency and optimum quality only can be achieved in a narrow range of intensity. The optical feedback resulting stochastically in temporal and spatial changes of intensity distribution controls surface finish and reproducibility that diagnostics and monitoring of laser intensity and mode structure during processing are essential requirements for optimum processing results. The heat flow governs the load and the losses of the heat affected zone with the different analytic and numerical models for the mathematical analysis of the multiparameter problem laser materials processing providing a testing comparison with the physical picture and an easy estimation of process parameters in applications.