"Nano" refers to a scale of measurement that is one billionth of a meter, or 10^-9 meters. This tiny scale is often used in fields like nanotechnology, which involves manipulating matter at the atomic and molecular levels. At this scale, materials can exhibit unique properties that differ from their larger counterparts, leading to innovative applications in electronics, medicine, and materials science. In nanomedicine, for example, nanoparticles can be used to deliver drugs directly to targeted cells, improving treatment effectiveness while minimizing side effects. The study of nanoscale materials also plays a crucial role in developing stronger, lighter materials for various industries, including aerospace and automotive.