Nanotechnology is helping to considerably improve, even revolutionize, many technology and industry sectors: information technology, energy, environmental science, medicine, homeland security, food safety and transportation, among many others. Today’s nanotechnology harnesses current progress in chemistry, physics, materials science and biotechnology to create novel materials that have unique properties because their structures are determined on the nanometre scale. This Chapter summarizes Fundamental Concepts in Nanoscience and Nanotechnology, types of nanoparticles, General classification and potential applications of NPs, Green nanotechnology, green synthesis, the various applications of nanotechnology.