Bridge girder is a main structural member laying horizontally as in buildings or bridges. It supports vertical loads and consists of a single piece or consists of more than one piece bound together.
Girder is a primary beams that are used at the place where wide space is available. This main beam which is also called as bridge girder in case of bridges, supports smaller beams and other structural components. Girders are made of built up sections and carry heavier loads over larger spans. Bridge girders or girders are supported directly on columns.