State Machine Diagram

"State machine diagram is a behavior diagram which shows discrete behavior of a part of designed system through finite state transitions. State machine diagrams can also be used to express the usage protocol of part of a system. Two kinds of state machines defined in UML 2.4 are:
(1) behavioral state machine, and
(2) protocol state machine.
The following nodes and edges are typically drawn in state machine diagram: behavioral state, behavioral transition, protocol state, protocol transition, different pseudostates. ...
Behavioral state machine is specialization of behavior and is used to specify discrete behavior of a part of designed system through finite state transitions. The state machine formalism used in this case is an object-based variant of Harel statecharts.
Behavior is modeled as a traversal of a graph of state nodes connected with transitions. Transitions are triggered by the dispatching of series of events. During the traversal, the state machine could also execute some activities. ...
Protocol state machine is a specialization of behavioral state machine and is used to express usage protocol or lifecycle of a classifier. It specifies which operations of the classifier can be called in which state and under which condition, thus specifying the allowed call sequences on the classifier’s operations. Protocol state machines express the legal transitions that a classifier can trigger." [uml-diagrams.org/ state-machine-diagrams.html]
The template "UML state machine diagram" for the ConceptDraw PRO diagramming and vector drawing software is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.
www.conceptdraw.com/ solution-park/ software-uml

The vector stencils library "UML state machine diagrams" contains 35 symbols for the ConceptDraw PRO diagramming and vector drawing software.
"The state diagram in the Unified Modeling Language is essentially a Harel statechart with standardized notation, which can describe many systems, from computer programs to business processes. In UML 2 the name has been changed to State Machine Diagram. The following are the basic notational elements that can be used to make up a diagram:
(1) Filled circle, pointing to the initial state.
(2) Hollow circle containing a smaller filled circle, indicating the final state (if any).
(3) Rounded rectangle, denoting a state. Top of the rectangle contains a name of the state. Can contain a horizontal line in the middle, below which the activities that are done in that state are indicated.
(4) Arrow, denoting transition. The name of the event (if any) causing this transition labels the arrow body. A guard expression may be added before a "/ " and enclosed in square-brackets ( eventName[guardExpression] ), denoting that this expression must be true for the transition to take place. If an action is performed during this transition, it is added to the label following a "/ " ( eventName[guardExpression]/ action ).
(5) Thick horizontal line with either x>1 lines entering and 1 line leaving or 1 line entering and x>1 lines leaving. These denote join/ fork, respectively." [State diagram (UML). Wikipedia]
The example "Design elements - UML state machine diagrams" is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.