Nanoparticles are all nano-scale structures that have at least one dimension in this scale (nanolayers, nanowires, nanospheres, etc.). Nano compounds are chemical compounds on the nano scale. This means that silver or copper at the nano scale are not nanocompounds, because they do not bonded with other atoms, while nanocopper oxide is a nanocompound, because it consists of combined atoms of copper with oxygen. Nanometals are pure metal nanoparticles. The safest is using of the term “nanoparticle” e.g. “silver nanoparticle” or “zinc oxide nanoparticle” because it covers the widest group of substances. Often, prefixes such as “nanotube”, “nanosphere”, “nanopyramide” or other of this kind appear and they determine the specific shape of the molecule.