An arch is a curved structure that spans an opening and supports weight from above. It is commonly made from materials like stone, brick, or concrete. Arches are often used in buildings, bridges, and aqueducts, providing both strength and aesthetic appeal. The design allows for the distribution of weight, making it possible to create larger openings without the need for solid walls. There are various types of arches, including the Roman arch, which is semi-circular, and the Gothic arch, known for its pointed shape. Arches have been used in architecture for thousands of years, showcasing their importance in both historical and modern construction.