Nanoparticle sizing refers to the measurement of the dimensions of nanoparticles, which are tiny particles typically ranging from 1 to 100 nanometers in size. Accurate sizing is crucial because the properties of nanoparticles, such as their reactivity and strength, can vary significantly with size. Various techniques, including dynamic light scattering and scanning electron microscopy, are used to determine the size distribution of nanoparticles. Understanding nanoparticle size is essential in fields like pharmaceuticals, where the effectiveness of drug delivery systems can depend on particle size. Additionally, in materials science, the performance of nanomaterials in applications like coatings and electronics is influenced by their size. Proper sizing ensures that nanoparticles can be effectively utilized in their intended applications.