The influence of adhesion on molecular conformations-besides solely molecule orientation-and vice versa was rarely considered in adhesion science due to the difficult analysis of conformational equilibria, in general, and the high number of possible conformations in classical polymers, in particular. Fortunately, some insight is available from the interphase chemistry of proteins due to the importance regarding their biological function in heterogeneous systems. Peptides and proteins are, thus, ideal model systems for the experimental and theoretical investigation of conformational changes in interphases. The conformational equilibrium of any kind of compound or, more specifically, a polymer interacting with a surface must differ in the interphase when compared with the bulk. This is also the case for common adhesives. Therefore, we define that the interphase of an adhesive bond is the area in which the chemical composition or the conformational equilibrium differs from that of the bulk phase.