Nanoparticles (NPs) can be categorized into several classes based on their composition and structure. Metallic nanoparticles (e.g., gold, silver) are used in imaging, drug delivery, and antimicrobial applications. Polymeric nanoparticles are formed from biodegradable polymers like PLGA and are often employed in drug delivery systems due to their controlled release properties. Lipid-based nanoparticles, including liposomes and solid lipid nanoparticles, are widely used for encapsulating drugs and enhancing bioavailability. Inorganic nanoparticles (e.g., silica, quantum dots) are used in diagnostics and biosensing. Lastly, carbon-based nanoparticles (e.g., fullerenes, graphene) have applications in drug delivery, imaging, and electronics.