This document provides an overview of nanotechnology including definitions, materials, fabrication methods, applications, and toxicity concerns. Nanotechnology involves manipulating matter at the nanoscale (100nm or less). Nanoparticles can be organic, inorganic, or composites and are synthesized through various physical and biological methods. Applications include drug delivery, cancer treatment, imaging, and tissue engineering. However, toxicity depends on factors like size, shape, and chemistry, as smaller nanoparticles may more readily interact with and potentially damage biological systems. The future promises revolutionary advances through nanotechnology but continued research is still needed into its impacts.