Single-molecule spectroscopy is a technique used to study individual molecules rather than bulk samples. This method allows scientists to observe the unique properties and behaviors of single molecules, providing insights into their structure, dynamics, and interactions. By using highly sensitive instruments, researchers can detect the light emitted or absorbed by a single molecule, revealing information that is often lost in traditional spectroscopy. This approach has applications in various fields, including biochemistry, materials science, and nanotechnology. It helps in understanding complex biological processes, such as protein folding and DNA interactions, and can lead to advancements in developing new materials and technologies.