This document discusses different types of bridges and their histories. It begins by defining what a bridge is and explaining that bridge designs vary based on their function and location. It then provides a brief history of bridge development from 700 AD to present day, including examples like Roman arch bridges and suspension bridges. The rest of the document defines and describes the six main types of bridges: beam, cantilever, arch, suspension, cable-stayed, and truss bridges. It also discusses floating bridges and culverts. Forces, materials, and spans for each bridge type are outlined.