This lecture delves into the analysis of the solutions of the forced oscillator differential equation, focusing on the excitation frequency parameter and the concept of resonance. By examining the general solution and the particular solution, the instructor explains the significance of the amplitude and phase shift in the forced oscillator system. The lecture also covers the distinction between transient and permanent regimes, showcasing how the system evolves from establishing oscillations to reaching a stable state. Through demonstrations with different damping mediums and varying excitation frequencies, the instructor illustrates how the amplitude and phase of the oscillations are influenced. The concept of resonance, where the system maximizes oscillations, is explored, emphasizing the importance of the permanent regime in forced oscillators.