What is a Beam?
A beam, in Structural Engineering terms, is a member that can be comprised of a number of materials (including steel, wood aluminium) to withstand loads - typically applied laterally to the beam axis. Beams can also be refered to members, elements, rafters, shafts or purlins.
A 3D Rendering of an I-Beam
Source: SkyCiv Beam
Beams can come in a wide range of shapes that have different applications and strength purposes. Some common shapes are i beams (as shown in the 3D renderer above), T-beams, channel sections, rectangular, hollow rectangular and pipes. Regardless of the shape, they are all considered beams. In analysis and design, they are often picked up from different manufacturer libraries and databases so that the industry is all modelling structures based on the same shapes and dimensions.