- This chapter discusses the deflection of beams under lateral loading. Deflection is the displacement of points on the beam's axis from its original, unloaded position. - The basic differential equation relates the bending moment to the second derivative of the deflection curve. This equation can be directly integrated or used with methods like Macaulay's to determine deflections. - Macaulay's method involves integrating the loading equation rather than the bending moment equation directly. It is useful when the bending moment is difficult to obtain. - Special cases like loads not starting from the beginning or ending at the beam's end are also discussed.