Life threatening and life forming events, like the spreading of cancer and embryogen- esis, are governed by how cells interact with each other and therefore by cell adhesion. Further, all cells are surrounded by membranes. Therefore, the understanding of membrane interactions is the foundation for evaluating the role of biological mem- branes in the process of cell adhesion. While the role of various adhesive proteins in this process is mostly dealt with by biology, physics can be used to analyze and describe the mechanistic details of the membrane. This makes membranes and their interactions a highly relevant and exciting field in biophysics.