This lecture covers the fundamental concepts of moments and beams in structural analysis. It begins with a review of elongation and shrinkage, followed by the deformation of bar networks. The instructor discusses the influence of static height and introduces the concept of moments in the sections of a truss. The lecture emphasizes the equilibrium of moments, explaining that a point is in rotational equilibrium if the sum of applied moments is zero. The relationship between beams and trusses is explored, highlighting the deformation of bars and beams. The lecture also addresses the internal sections of beams, detailing the applied moments and shear forces. The impact of discretization of loads on moment distribution is analyzed, demonstrating how finer discretization leads to a more accurate representation of bending moments. The session concludes with examples of beams under various support conditions, reinforcing the principles discussed throughout the lecture.