Beam Theory is a fundamental concept in structural engineering that analyzes how beams support loads. It helps engineers understand how beams bend and deform under various forces, such as weight or pressure. The theory simplifies complex structures by treating beams as one-dimensional elements, allowing for easier calculations of stress and deflection. In Beam Theory, key assumptions include that the material is elastic and homogeneous, meaning it behaves consistently under stress. The theory also assumes that the beam's cross-section remains unchanged during bending. This approach is essential for designing safe and efficient structures, such as bridges and buildings, ensuring they can withstand applied loads without failure.