There are many forms of nanotechnology, the field is interdisciplinary. The term nanotechnology is used with different meanings in physics, chemistry, biology, medicine and materials science, but common is that nanotechnology deals with understanding and controlled production of nano structures.
When working with nanotechnology, it is important to understand that there is a big difference between the macro and nano scale.
This is the case when working with physical, optical, mechanical or chemical properties at the nano scale. Example, aluminum becomes explosive in nano size, and color of the gold particles can change from gold to green, orange, purple or red depending on the size of the particles