Beam theory is a fundamental concept in structural engineering that analyzes how beams support loads. It helps predict how beams will deform and distribute forces when subjected to various loads, such as weight or pressure. The theory simplifies complex structures by treating beams as one-dimensional elements, allowing engineers to calculate bending moments, shear forces, and deflections. In beam theory, assumptions are made, such as the beam being straight, homogeneous, and elastic. These assumptions enable the use of mathematical equations to model the behavior of beams under different conditions. Common applications include designing bridges, buildings, and other structures where beams play a crucial role in maintaining stability and safety.