Answer:
A) Body forces-
Body forces is the forces which acts throughout the volume of the body. It is basically distributed over the volume and mass of the element of the body. In a body force other body exerts a force without being contract.
For example : Gravity forces, electromagnetic forces, centrifugal forces.
B) Surface forces-
Surface forces is the forces which are distributed all over the free surface of the body. Surfaces forces can be further divided into two perpendicular components as: normal forces and shear forces.
For example : Pressure forces and viscous forces.