Nanotechnology is a promising science based on length scales (between 1-100 nanometers). It is not a single entity but an interdisciplinary domain which incorporates physics, chemistry, material science, electronics, and biotechnology. Nanoscale particles, materials and devices can be fabricated using either “bottom-up” or “top-down” fabrication approaches. The top- down approach involves the breaking down of bulk material into nanosized units through techniques like photolithography, nanomolding, dip-pen lithography, nanofluids and precision engineering. Conversely, contemporary and commonly used bottom-up approach for synthesis of nano -substances is concerned with build-up of nanostructures atom by atom or molecule by molecule through various physical, chemical processes, self assembly and positional techniques. Newer Green technology uses the plant extracts or live plants or their parts to synthesize inorganic as well as organic nanoparticles. Green synthesis enjoys advantages of being environment- friendly synthesis process, high scalability, simple one-pot reaction overcoming limitations and cumbersome process of fabrication by physical and chemical means In medicine, the enormous implications for diagnostic, therapeutic use to improve drug-delivery, bioavailability, efficacy and decrease in adverse effects compel their wide use in various diseases like cancer, infections, inflammation and delayed would healing. The wider applicability, easier and eco friendly nature has ascertained the further development of nanotechnology in times to come.