What is Nanotechnology?

What is Nanotechnology?

From: 

http://www.crnano.org/whatis.htm

A basic definition: Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced.In its original sense, 'nanotechnology' refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products.

Plus in :

http://www.crnano.org/whatis.htm