Abutment is a type of column which is constructed towards approach road of a bridge. Pier is a type of column which is in between two abutments. Abutment and pier need to withstand wind and seismic load in addition to the load transferred to it from beams and are called substructure of bridge.

Span is the distance between two intermediate supports for a structure, e.g. a beam or a bridge. A span can be closed by a solid beam or by a rope. The first kind is used for bridges, the second one for power lines, overhead telecommunication lines, some type of antennas or for aerial tramways.