Surface treatment refers to various processes applied to the outer layer of a material to enhance its properties. These treatments can improve characteristics such as corrosion resistance, wear resistance, and adhesion. Common methods include painting, coating, polishing, and plating, which are often used on metals, plastics, and wood. The choice of surface treatment depends on the intended use of the material. For example, automotive parts may undergo galvanization to prevent rust, while furniture might be treated with varnish for a smooth finish. Overall, surface treatments play a crucial role in extending the lifespan and functionality of products.