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 Unified Modeling Language specification, (v2.5.1, p.313) states:
An entryPoint Pseudostate represents an entry point for a StateMachine or a composite State that provides encapsulation of the insides of the State or StateMachine. In each Region of the StateMachine or composite State owning the entryPoint, there is at most a single Transition from the entry point to a Vertex within that Region.