# State Diagram
**A diagram describing the behaviour of a system as a set of states and the transitions between them.**
A *state diagram* is a diagram that represents the behaviour of a system that has several states with transitions between them. They are often [[Graph#Directed graph|directed graphs]] in which the vertices represent states and the edges represent transitions.
## Finite state machines
### Mealy machine
For a [[Finite State Transducer#Mealy machine|Mealy machine]], outputs are labelled on a transition with the inputs as $j/k$ with $j$ as the input and $k$ as the output.
![[MealyStateDiagram.svg|500]]
### Moore machine
For a [[Finite State Transducer#Moore machine|Moore machine]], outputs are labelled on its associated state.
![[MooreStateDiagram.svg|500]]