Nano refers to a nanometre (nm). One nanometre is one-millionth of a millimetre and a single human hair is around 80,000 nanometres in width! Nanotechnology refers to a field of applied science and technology whose theme is the control of matter on the atomic and molecular scale, generally 100 nanometers or smaller, and the fabrication of devices or materials that lie within that size range.Nanoscience and nanotechnology involve studying and working with matter on an ultra-small scale.
(Human hair fragment and a network of single-walled carbon nanotubes )
Nanotechnologies are widely seen as having huge potential in areas as diverse as healthcare, IT and energy storage. Governments and businesses across the world have started to invest substantially in their development.
For Further reading,