Both beam and column are vital parts of buildings. Nowadays, we can not imagine stable multi-storey building without these components. Beams are the horizontal part of building, which carries tensile load and shifts it to columns whereas columns are vertical members, which carry compressive load and shifts it to foundation.
Beams are made to carry load perpendicular to longitudinal axis but columns carry load parallel to longitudinal axis. Columns can be of circular shape but beams can never be of circular shape. Buildings can be built without beams but columns are the basic part of any building.
Beams are classified according to their support while columns are classified on the basis of their slenderness ratio. The failure of beam is not sudden while the failure of column is sudden which results in collapsing of entire structure.
Beams are generally casted with slab and needs strict observation in case of RCC structures whereas columns are casted in small batches in case of RCC structures.