Collinear forces act along the same line of action, concurrent forces pass through a common point and coplanar forces act in a common plane.

Normal force (F_N) represents the force a surface exerts when an object presses against it.

A concentrated load acts on a relatively small area of a structure, a static uniformly distributed load doesn't create specific stress points or vary with time, a dynamic load varies with time or affects a structure that experiences a high degree of movement, an impact load is sudden and for a relatively short duration and a non-uniformly distributed load creates different stresses at different locations on a structure.