What is nanotechnology?

As a definition, nanotechnology is the control of matter on the atomic and molecular scale.
The name nano comes from the size of molecules which is measured in nanometers (one billionth of a meter).
Why nanotechnology is very important? The answer is given by nature in this classical example that we all know from primary school. Think about diamond and coal, the only difference between those materials is the arrangement of carbon atoms so, if you can imagine a technology that enable us to manipulate material at atomic scale you can perceive the importance of nanotechnology.

Examples of nanotechnology in modern use are the manufacture of polymers based on molecular structure, and the design of computer chip layouts based on surface science. Despite the great promise of numerous nanotechnologies such as quantum dots and nanotubes, real commercial applications have mainly used the advantages of colloidal nanoparticles in bulk form, such as suntan lotion, cosmetics, protective coatings, and stain resistant clothing.