The standard unit of length used by scientists is the meter which is something most people can conceptualize. If you were to take a meter stick and break it into 100 pieces all of equal length you would get pieces that were 1 centimeter long. Again it is pretty easy for someone to understand something of this length. For instance your finger nails are approximately 1 centimeter in width. Now let's take one of those pieces of the meter stick and break it into 10 equal length pieces and we now have pieces that are 1 millimeter in length. One millimeter is about the width of a pinhead or the length of a flea. Now take one of these millimeter pieces and break it into ten thousand equal length pieces. This process will result in pieces that are 100 nanometers in length, which is about half the length of the rabies virus. Simply put one nanometer is one billionth of a meter. That's nine orders of magnitude smaller than a meter. As you can see it is hard to conceptualize things this small, but things ranging from one to 999 nanometers are considered "nanoscale" and this scale is where the field of Nanoscience begins. To put this in better perspective most atoms are about one to two orders of magnitude smaller than this range still. Thus Nanoscience deals with things that are made up of lots of atoms, and the weird properties they exhibit on this scale.