What Is a Bridge?
A bridge is a structure that spans an obstacle such as a river, valley, or roadway and connects two points. Bridges are typically constructed from concrete, steel, stone, wood, or other materials depending on the purpose of the bridge and its location. The most common type of bridge is known as a beam bridge which consists of one or more horizontal beams supported by piers at either end. Other types include arch bridges which use curved arches to span obstacles; suspension bridges which hang from cables suspended between towers; truss bridges with triangular frames for support; cantilever bridges where one side is anchored while the other extends outward; and cable-stayed bridges in which vertical columns hold up the decking.
Bridges can be used for many purposes including transportation (roadways), recreation (pedestrian walkways), irrigation systems (aqueducts) and even military defense structures (fortifications). In addition to providing access across physical barriers they also provide aesthetic value to their surroundings often becoming iconic landmarks in cities around the world. As technology advances so do our abilities to construct larger and stronger bridges allowing us to traverse greater distances than ever before!