This paper reviews the progress in the understanding of plasma surface interactions. The understanding of the surface kinetics of plasma surface interactions is critical in the efficient development of plasma processes. Our fundamental understanding of plasma-surface interactions has in large part been based on beam experiments in which the flux from a plasma process is synthesized by a combination of beams. The use of beams rather than a plasma source allows the independent control of the beam fluxes. The measurement of polysilicon etching in fluorine and chlorine plasmas has been particularly successful because of its relatively simple discharge chemistry; however, the inclusion of product and polymer deposition during the etching process has typically not been included in kinetic models. The etching of dielectric materials with fluorocarbon gases is much more complex because of the large number of ions and neutral species that must be considered. The use of beams generated from complex plasmas that produce multiple products can be used to better represent the fluxes; however, these studies sacrifice some independence in the control of the fluxes. Based on the kinetic measurements and kinetic models developed from the beam studies, feature profile evolution has been modeled using several approaches, especially Monte Carlo techniques that allow the inclusion of all known kinetics. Deposition processes in which the surface is covered with a material of a single composition is particularly easy as the surface chemistry is does not vary with time or feature position. In etching processes, the surface kinetics are known to be a function of the composition of the feature position and is more complicated since the surface composition varies. In addition, for the deposition of “polymer film” onto the surface during etching to be included for direction etching processes, the polymer film thickness and composition must be tracked as the simulation proceeds.