To answer the question that what is nanotechnology, let us first discuss nanoscale because nanotechnology is a science that deals with objects in nanoscale. Nano means 10^-9 or one billionth. For example, nano meter means 10^-9 meter. Therefore nanotechnology is the science that deals with the objects in size 1 nm. Sometimes the range is defined to 1 to 100 nm.

The scientists also called this as top-down science. The biological, chemical and physical properties associated with the nanostructure particles constituted from atoms and molecules is known as bottom-up process. The top-down process refers to machining and etching techniques and the bottom-up process constitute building organic and inorganic structures atom-by-atom.

In nanotechnology basic properties of materials depend on their size. For example, a nano size wire does not necessarily obey Ohm’s law.

There are many unusual properties of nano size particles that we will discuss later on with the applications of nanotechnology. For example, gold is not just of gold color in nano size and it may be of different colors