Diffuse Interface Field Approach (DIFA) is the most advanced meso-scale computational technique for simulating microstructure evolutions and materials properties. This book presents DIFA's applications to a wide variety of material processes, including non-linear diffusion, spinodal decomposition, precipitation, ordering, martensitic phase transformation, ferroelectric and ferromagnetic phase transitions, dislocations, cracks, voids, grain growth, sintering, corrosion, and more. It focuses on solid-state material processes and cover topics from fundamental concepts to state-of-the-art practices, giving students, professionals, and researchers the first single source reference on the topic.