In short, a nanometer is a millionth of a millimeter. If this is to put in perspective, a nanometer is about 100,000 times smaller than the thickness of something as thin as a human hair. To clarify the size further, it can be said that the ratio between a nanometer and a soccer ball (size 5 ) corresponds to the ratio between a football and the globe.
If you work with nanotechnology, in other words when working with something that is less than 100 nanometers (nm) in size- it is very, very small. When a material is processed in nano form, this changes the physical, chemical and biological properties in a very fundamental way. If you work at the nanoscale, then you have ample opportunity to tailor the respective materials with special properties, so many leading thinkers have the belief that nanotechnology may result in an industrial revolution much like the inventions of the steam engine, electricity and computer technology.