Signal-flow graph
A SPECIALIZED FLOW GRAPH, A DIRECTED GRAPH IN WHICH NODES REPRESENT SYSTEM VARIABLES, AND BRANCHES (EDGES, ARCS, OR ARROWS) REPRESENT FUNCTIONAL CONNECTIONS BETWEEN PAIRS OF NODES
Mason graph; Signal flow graph
A signal-flow graph or signal-flowgraph (SFG), invented by Claude Shannon, but often called a Mason graph after Samuel Jefferson Mason who coined the term, is a specialized flow graph, a directed graph in which nodes represent system variables, and branches (edges, arcs, or arrows) represent functional connections between pairs of nodes. Thus, signal-flow graph theory builds on that of directed graphs (also called digraphs), which includes as well that of oriented graphs.