The interaction between a protein molecule and a surface is ubiquitous to a number of important technologies, such as bio-sensing, biomaterials, and nanomedicine. This process is also essential to complex biological functions, such as protein–cell surface interactions. Here we explore the application of fundamental concepts developed in the field of surface science to the understanding of protein–surface interactions. In particular, we focus on the role of mobile precursor states in the reversible and irreversible adsorption of protein molecules. We attempt to apply these simple concepts to the analysis of the kinetics and thermodynamics of protein–surface interactions. We conclude by discussing how one may take advantage of these simple concepts in designing and controlling protein–surface interactions for various bio-interface based technologies.