This lecture explains the analysis of a system with conjugate complex poles when the damping ratio is less than one. The instructor demonstrates the step-by-step process of finding the system's response, including deriving the Laplace transform, solving for the coefficients, and analyzing the frequency and decay of the oscillations. By varying the damping ratio, the lecture illustrates how the system's response changes in terms of frequency and decay rate, emphasizing the relationship between damping, oscillation amplitude, and response speed.