What is the difference between a pier and a column?

“Pier is usually used as a general term for any type of substructure located between horizontal spans and
foundations. However, from time to time, it is also used particularly for a solid wall in order to
distinguish it from columns or bents. From a structural point of view, a column is a member that resists
the lateral force mainly by flexure action whereas a pier is a member that resists the lateral force mainly
by a shear mechanism.”

Wang, J. “Piers and Columns.” Bridge Engineering Handbook, Ed. Wai-Fah Chen and Lian Duan
Boca Raton: CRC Press, 2000