A flow chart is used for combinatorial design. It is a stateless flow chart because it cannot maintain its active state between updates. As a result, a flow chart always begins executing from a default transition and ends at a terminating junction (a junction that has no valid outgoing transitions).
By contrast, a state transition diagram is used for sequential design. It stores its current state in memory to preserve local data and activity between updates. As a result, state diagrams can begin executing where they left off in the previous time step, making them suitable for modeling reactive or supervisory systems that depend on history. In these kinds of systems, the current result depends on a previous result.