Selective Catalytic Reduction (SCR) is a technology used to reduce harmful emissions from diesel engines. It works by injecting a solution of urea into the exhaust stream, which reacts with nitrogen oxides (NOx) in the presence of a catalyst. This process converts NOx into harmless nitrogen and water vapor, helping to meet environmental regulations. SCR systems are commonly found in heavy-duty vehicles, such as trucks and buses, as well as in industrial applications. By improving air quality and reducing pollution, SCR plays a crucial role in promoting cleaner transportation and supporting sustainability efforts.