What is the difference between a beam and a column?

Beams are longitudinal members that supports vertical loads or moments, while columns are vertical members that supports axial and lateral loads. Moreover, in structural analysis, beam loads are transferred to columns. 

Beams can withstand tension, compression and moment(torsion), while columns are compression members only but they also withstand moments.

Column is Compression member and Beam is Bending members.

Many people says beam is a structural member which carries transverse loading by moment of resistance and shear strength. They say that beam donot carry axial loading and columns donot carry transverse loading. Think of prestressed beam which carries load of prestress by local compression which is axial and in fully prestressed beam, by compression only. Think of the case of a column which is connected to a hydraulic jack in horizontal direction, loading is transverse but column is never called as beam. Beam is a horizontally oriented load carrying structural member and column is a vertically oriented load carrying structural member with reference to global co ordinate system. But remember that the beam theories are associated with beams loaded transversely , similarly columns. I wish to elaborate the answer later

- Both, the beams and columns are load carrying elements, but differ in the method or the way of handling the load by each member. That means, the columns bear the compression of the load, whereas  beams bear the bending moment and the shear force of the load.

- Similar materials are used in the construction of columns and beams, which are steel, timber and concrete.

- A building can’t stand without columns but a building can stand without beams.

- Design classifications of beams and columns are different. Column are classified as slender or short, while beams are classified as T,L or rectangular.

- The ties of the columns and the ties or shear reinforcement of beams act differently.

- One should be careful in stating the behavior of each, because the behaviors of the two elements are different.

• beam is tension compression member. column is axial compression member.....
• beam is generally horizontal , column is generally vertical..
• beam is besically resists bending and shear force. column resists vertical axial force...