The main scope of this work is to examine and evaluate the roles of different aspects of adsorption science and technology (namely, the roles of the characteristics of the adsorbents, properties of the adsorbed molecules, interactions between the surface of the adsorbent and the adsorbed molecules, and among each of the adsorbed molecules and the others, thermodynamic properties of the adsorbed phase, and non-equilibrium dynamic behavior of the adsorption phenomenon) on the proper description of the adsorption phenomenon and prediction of the adsorption process behaviors.