Nanotechnology involves manipulating materials at the nanoscale, which is approximately 1 to 100 nanometers. The document discusses the history and definition of nanotechnology, provides examples of nanostructures and nanomaterials, and describes various types of nanoclay structures and their preparation. Nanocomposites are introduced as materials made of two or more components where at least one is a nanomaterial. The document outlines some key applications of nanotechnology in areas like materials, electronics, and healthcare.