Initial   An initial is a kind of pseudostate that represents the starting point in a region of a state machine. It has a single outgoing transition to the default state of the enclosing region, and has no incoming transitions. There can be one (and only one) initial state in any given region of a state machine. It is not itself a state but acts as a marker.

Explanation

The initial state is the starting point for any level of a state machine. It is not a state itself but simply marks the starting point for any level. There are often a number of start states on a diagram but there can be only one for each composite level of a state machine.

Important Points

There can be one (and only one) initial state at any level of nesting in a state machine.

A state machine can have one and only one initial state at any level. The initial state acts as a marker and is the default entry point for any incoming transition that connects to the enclosing state?s perimeter.

Related Entries

Final State  Graphically Similar,  Paired Element The final state is related to the initial in the sense that it represents the condition (or conditions if there are more than one) that the enclosing state can end in. While it is a paired element with the initial state and they have a similar appearance, the meaning of the two elements is quite different. A final state is formally itself a state whereas an initial is not itself a state but a pseudostate, which acts as a kind of placeholder or representation of a state. It is also important to remember that there can be one (and only one) initial pseudostate at any level in a composite state, but there can be many final states at the same level.