This text provides basic and novel ideas on how to use spatial solitons. The emphasis is on both mathematical and physical formulations, concentrating on diffraction-based spatial effects. The text shows how important self-focusing is, and how to see it in operation, in simulation and experimentally. The use of spatial solitons is driven by the need for all-optical, chip-based processing. With its wide-ranging treatment, from magneto-optics to fascinating vortex phenomena, the book is a repository of information. It should prove a valuable asset in any research laboratory interested in all-optical, chip-level processing.