Entry Point pseudostates are used to define the beginning of a StateMachine. An Entry Point exists for each region, directing the initial concurrent state configuration.
OMG UML Specification:
The OMG UML specification (UML Superstructure Specification, v2.1.1, p.471) states:
An entry point pseudostate is an entry point of a state machine or composite state. In each region of the state machine or composite state it has a single transition to a vertex within the same region.