This lecture covers flow networks, flows, and the Ford-Fulkerson Method. It explains the formal definition of a flow network, the concept of flow, and the method for finding maximum flow in a network. The instructor introduces the Ford-Fulkerson Method, detailing the steps involved and providing examples of its application. The lecture also discusses residual networks, cuts in flow networks, and the calculation of net flow across a cut. Various definitions and constraints related to flow networks are explored, emphasizing the importance of capacity constraints and conservation principles.