The concept of "maximum flow" refers to the greatest amount of flow that can be sent from a source node to a sink node in a flow network. A flow network consists of nodes connected by edges, each with a specific capacity that limits the flow. The goal is to determine how to route the flow through the network without exceeding these capacities. To find the maximum flow, algorithms like the Ford-Fulkerson method or the Edmonds-Karp algorithm are often used. These algorithms systematically explore paths from the source to the sink, adjusting the flow until no more can be sent without violating capacity constraints.