This lecture introduces the image charge method, explaining how to use it to find solutions to the Poisson equation and calculate potentials. The instructor demonstrates the process step by step, showing how to place image charges outside the region of interest to satisfy boundary conditions and ensure uniqueness of the solution. Through detailed examples, the lecture covers scenarios with single charges, pairs of charges, and infinite planes, illustrating how to determine the configuration of image charges to accurately calculate potentials. The instructor emphasizes the importance of placing image charges outside the region being analyzed and highlights the iterative process of adding new images until the boundary conditions are met, ensuring an accurate solution.