The concept of nanoscience and nanotechnology emerged when the famous physicist Richard Feynman's talk entitled "There's Plenty of Room at the Bottom". Nanoscience and Nanotechnology both are the branches of science, where nanoscience deals with the synthesis, manipulation and characterization of the particles at atomic, molecular and macromolecular level, having at least one dimension in the range of 1-100 nanometer. Nanotechnology is all about application of nanoscience in the field of design, characterization, fabrication, and application of structure, devices, and system by controlling shape, size, and structure at the nano level. These nanostructured materials and technical development in the arena enable its application in various fields like Automobile, Space Physics, Textile, Medicine, Agriculture, Biotechnology, etc. This book deals with the basic terms and definitions, Main features of nanoparticles, size and structure-dependent properties, synthesis and characterization techniques for nanostructured materials.