A body can be subjected to two different classifications of forces, namely surface forces, and body forces.
SURFACE FORCES are caused by the DIRECT CONTACT of one body with the surface of another. Examples include concentrated (or point) loads, which are applied to a point on a body, and linearly distributed loads, in which case the surface loading is applied along a narrow area.
BODY FORCES are developed when a body exerts a force on another body WITHOUT DIRECT or PHYSICAL CONTACT between the bodies. Examples include gravitational and electromagnetic forces acting on a body.