Self-cleaning windows are designed to reduce the need for manual cleaning. They are coated with a special layer that uses sunlight to break down dirt and grime. When it rains, the water helps wash away the loosened debris, keeping the windows clearer for longer periods. These windows typically use a technology called photocatalysis, which involves a chemical reaction activated by UV light. This process helps to decompose organic materials, making it easier for rainwater to rinse away the residue. Self-cleaning windows are popular in both residential and commercial buildings for their convenience and maintenance benefits.