Hauntings are the constant manifestation of spiritual entities that is attached around a person, place, or thing. These hauntings can occur in many ways, and by how they do manifest they can be placed into different categories.
Intelligent haunting also sometimes referred to as a traditional ghost are spiritual manifestations brought on by the spirit of a deceased human, or non-human animal. These are entities who died, and for some reason did not cross over through the liminal space between this plane, and the next. Entities may not cross over on death, if they are killed in a traumatic way, or if they have unfinished business. These entities are usually attached to some form of physical object in order to keep themselves grounded to the physical world.
Residual hauntings sometimes referred to as echoes are hauntings brought on by negative traumatic events which leave an imprint of that event spiritually in a specific place, or connected to a specific item. Spiritual imprint of the traumatic event usually will play over, and over again in the area like a movie, allowing the replay to interact with the physical world through its manifestation.
Poltergeist hauntings is the accidental creation of a thought-form entity by an individual from negative events. Poltergeists are usually created by individuals that are younger, and have a very strong connection to spiritual gifts. These poltergeists usually end up acting out the individuals negative will, and terrorizing individuals that are close to them. Poltergeist will usually be destroyed by the one who creates them, or will cease to exist once the negative events have been worked through.
Inhuman hauntings also sometimes referred to as non incarnate hauntings is a hunting brought on by any spiritual entity which never went to the process of having a physical incarnation. This is a hunting that is brought on by nature spirits, elementals, or a form of spiritual parasite. This haunting is usually caused by angering these types of entities, or by the entity trying to feed off your energy.
Portal hauntings are areas in which an unchecked amount of liminal space has opened, and multiple different forms of entities are attracted to manifesting there. Portals can be opened by individuals who practice occultism, or portals could be natural parts of the landscape. Entities that come through these portals can interact with the physical world, and can cause discord, and chaos if it is not put in check.