Pile, in building construction, a post like foundation member used from prehistoric times. In modern civil engineering, piles of timber, steel, or concrete are driven into the ground to support a structure; bridge piers may be supported on groups of large-diameter piles.
Pile foundation is needed in areas where the structures constructed are large & heavy and the soil underlying is weak.
In areas where settlement issues are common due to soil liquefaction or water table issues, pile foundation is a better choice.