The document discusses stress analysis, which determines the strains and stresses in engineering structures subjected to forces. Stress analysis is used by civil, mechanical, and aerospace engineers to design structures, investigate failures, and perform maintenance. It involves determining geometry, material properties, loads, and connections, then calculating deflections, strains, and stresses through mathematical or computational methods. The output data quantitatively describes strains, deflections, and how applied forces spread and cause stresses throughout the structure.