Nanoscience and nanotechnology concern themselves with the research and application of extremely small things and can be used across all scientific fields such as physics, chemistry, biology, material science and engineering. Nanoparticles are of great scientific interest as they provide a bridge between bulk materials and atomic or molecular structures. Interesting and unexpected properties of nanoparticles are largely due to the large surface area of the material.Nanoparticles of noble metals including silver (Ag) attract the interest of many researchers owing to their high potential for plasmonic devices in future. On the other hand, nanoparticles of silver (Ag) and silver halides (AgX) have played central roles and have been extensively studied for manyyears in silver halide (AgX) photography.Combining knowledge of nanoparticles of Ag and related materials in plasmonics and AgX photography, this book reinforces already existing knowledge, but also presents new ideas for metal nanoparticles in plasmonics. The first part examines the structure and formation of nanoparticles of Ag and related materials. Systematic descriptions of the structure and preparation of Ag, Au, and other noble metal nanoparticles for plasmonics are followed by and related to those of nanoparticles of Ag andAgX in AgX photography. The exploration of the structure and preparation of Ag and AgX nanoparticles in photography incorporates nanoparticles with widely varied sizes, shapes, and structures, and formation processes from nucleation to growth. The second part describes the properties and performancesof nanoparticles of Ag and related materials, including chapters on light absorption and scattering, catalysis, photovoltaic effects, and stability. The accumulated knowledge of many years of research in AgX photography is analysed and explained to deepen the readers knowledge on metal nanoparticles for plasmonics, catalysis, and photovoltaics with new ideas arising from the interaction between them.