Plasmonic nanostructures are tiny metallic structures, often made from materials like gold or silver, that can manipulate light at the nanoscale. They exploit the interaction between light and free electrons in metals, creating localized surface plasmons. This phenomenon enhances light-matter interactions, making these structures useful in various applications, including sensors and imaging. These nanostructures can be designed in various shapes, such as nanoparticles, nanorods, or nanodisks, to achieve specific optical properties. Their ability to concentrate light in small volumes allows for improved performance in technologies like photovoltaics and catalysis, paving the way for advancements in nanotechnology and materials science.