A diagram that represents the relationship between states in state space control. For discrete state systems, each state is explicitly represented by a circle with an appropriate name or identifier, while state transitions are represented by arrows connecting states, labelled with the relevant inputs and outputs.

A state diagram for dynamical state systems uses boxes to represent complex transfer functions, and circles to represent simpler ways to combine signals, such as summation. These are connected by arrows showing the continuous signal flow. In these diagrams the states are implicit.

State diagram – discrete

State diagram – dynamic