beams are commonly made of structural steel but may also be formed from aluminium or other materials. A common type of I-beam is the rolled steel joist (RSJ)—sometimes incorrectly rendered as reinforced steel joist.Structural steel is a category of steel used as a construction material for making structural steel shapes. A structural steel shape is a profile, formed with a specific cross section and following certain standards for chemical composition and mechanical properties.A beam is a structural element that primarily resists loads applied laterally to the beam’s axis. Its mode of deflection is primarily by bending. Beams are characterized by their manner of support, profile (shape of cross-section), length, and their material.Most metals used for construction purposes are alloys. For example, steel is an alloy with iron and carbon being the primary elements. Generally, iron-carbon alloys with up to 2.1% carbon by weight are considered steel and iron-carbon alloys with greater amounts of carbon are cast iron.One of the main reasons steel is used in so many construction projects is its durability—it has the highest strength-to-weight ratio of any other building material, making it ideal for buildings both large and small.In building construction, a beam is a horizontal member spanning an opening and carrying a load that may be a brick or stone wall above the opening, in which case the beam is often called a lintel (see post-and-lintel system).If you need to understand the basic difference between them, then one can simply say both are same material wise. If you keep it horizontally it is called a Beam which carries the loads by bending, simply called flexure. If you keep it vertically forms a Column which carries load by undergoing compression.