The differences between poltergeist activity and a haunting can be very hard to distinguish. In the early stages of a poltergeist it may be impossible. Involves the ghosts of deceased human beings appearing frequently in certain places and times. There are theories are that poltergeists are mass forms of PK energy that a living person is unknowingly controlling. In some cases extreme poltergeists activity has been linked to demons.
Poltergeist energies can travel anywhere with anyone.
Nearing the climax of the energy cycle poltergeists can become dangerous, inflicting both mental and physical terror in extreme cases.