There are three kind of stresses structural engineers see on a daily basis. These stresses can arise from from various kinds of loading acting on a structure. These three stresses are Normal Stress, Shear Stress & Flexure or Bending Stress. These stresses are important to keep in mind before designing any structure.
A normal stress is a stress that occurs when a member is loaded by an axial force. A normal stress occurs when an object encounters tension or compression.
Unlike normal stress which has a perpendicular load, shear stress results when a load is applied parallel to an area.
Bending stress is essentially a more specific type of normal stress. When a member experiences bending stress the top fibers of the beam undergo a normal compressive stress. The stress at the horizontal plane of the neutral is zero. The bottom fibers of the beam undergo a normal tensile stress. Calculating the maximum bending stress is crucial for determining the adequacy of beams, rafters, joists, etc.
While most programs do account for stresses in their calculations it is still important to keep them in mind before doing any design.