The lives of binary and multiple stars begin in their cradles in dark clouds, such as those in Taurus and Orion, and end with the high-energy infernos of supernova explosions and bright X-ray binaries. It has become clear that there is a common thread that runs through all of our understanding of binary evolution: the set of physical processes which they each undergo at various stages of their evolution. This volume provides an up-to-date review of binary stellar structure and evolution, considering these processes not just from the point of view of understanding the basic physics involved, but also with the aim of showing how similar processes apply to disparate groups of stars, and how a realization of this fact can lead to a better understanding of the field as a whole. Examples of such processes are the behaviour of discs around stars and binaries, the effects of the distortion of finite-sized stars in a binary, both on the stars themselves and on the orbit, and strong interactions between stars, such as mass transfer, common-envelope evolution and collisions.