Solid-state NMR is a research area that focuses on using nuclear magnetic resonance (NMR) spectroscopy to study the structure and dynamics of solid materials. This technique allows researchers to investigate the atomic-level structure and interactions of solid materials, such as crystals, polymers, and biological molecules, without the need for a traditional liquid or solution sample. Solid-state NMR is particularly useful for studying materials that are insoluble, unstable in solution, or have complex structures. It has applications in a wide range of fields, including materials science, chemistry, physics, and biology.