This book sets out the principles of parallel computing, explaining why, where, and how parallel computing is used. It is unique in its coverage of both conventional and neural computing (which act in ways similar to human brains), and also covers such topics as the fundamental paradigms employed in the field, how systems are programmed or trained, technical aspects including connectivity and processing element complexity, and how system performance is estimated (and why doing so is difficult). The penultimate chapter comprises a set of case studies of archetypal parallel computers, each study written by an individual closely connected with the system in question. The final chapter correlates the various aspects of parallel computing into a taxonomy of systems.