Beam - The beam type is the simplest type of bridge. The beam bridge could be anything as simple as a plank of wood to a complex structure. It is made of two or more supports which hold up a beam.

Arch - In the arch type of bridge, weight is carried outward along two paths, curving toward the ground.

Suspension/Cable-stayed - The deck (trafficway) of a suspension bridge is hung by cables which hang from towers. The cables transfer the weight to the towers, which transfer the weight to the ground.
Cable-stayed bridges have towers, but cables from the towers go directly to the road deck, instead of spanning from tower to tower.

Cantilever - In the cantilever type of bridge, two beams support another beam, which is where the deck or trafficway is. The two beams must be anchored, and this must be done well.