A structure in which at least one of the dimensions is about a nanometre. If one dimension is about a nanometre, the structure is called a nanotextured surface; if two dimensions, it is called a nanotube; if three dimensions, it is a nanoparticle. Specific examples of nanostructures are nanocomposites, quantum dots, and quantum heterostructures. The process of making a nanostructure is called nanostructuring. See also Nanophysics (Feature).