There are numerous types of bridges, including arch bridges, beam bridges, truss bridges, cantilever bridges and suspension bridges. There are a few other types of bridges as well, but they typically can be listed under the above categories as they are adaptations of these main types.
Arch bridges utilize archways or arches as the main structural component. In most cases, the usable part of the bridge -- the part containing the pathway or roadway -- is placed upon a series of arches.
Perhaps the most basic of all bridges, beam bridges are supported by several beams, which can vary in shape and size. Truss bridges are built using diagonal posts. There are two main types of truss bridges, including the king post design and the queen post design.
Although they resemble arch bridges, cantilever bridges are supported by diagonal braces or trusses rather than the vertical braces used in arch bridges. Suspension bridges are suspended using a series of heavy, thick cables which are connected to columns. Cables are attached using a harp design, which resembles the strings of a harp, or a fan design in which all cables connect at one point. A famous example of a fan design is the San Francisco Bridge.