Apparition - A disembodied spirit visible to the human eye.

Cold Spot - An area that is noticeable colder than its surroundings.  It is believed by some that the presence of a spirit drawing energy from its environment in an attempt to manifest can create this effect.

DVR - Digital Voice Recorder.  These are used to record possible audio evidence, such as EVP's.

EMF Meter - Electromagnetic Field Meter.  It is a device used to record fluxuations in EMF fields.  It is believed that a fluxuation in an EMF field can be caused by the presence of a spirit in the area.  On the other hand, everyday stuff can cause EMF fields as well....such as power lines, appliances, television sets, etc.

EVP - Electronic Voice Phenomenon.  An EVP is a disembodied voice recorded on an audio device that was not audible to the human ear at the time.

Inhuman Entity - A negative spirit, or demon meaning to cause harm to those living.

Intelligent Haunting - An entity aware of its surroundings, and tries to interact with the living.

Matrixing - The human mind can add details to sensory input to create a familiar or more easily understood pattern.  For example, if you stare at a picture too long, it can begin to look like something that it is not.

Phantom Smell - A scent by which an entity is trying to express itself.

Poltergeist Haunting - An entity that shows its presence through noises, the moving of objects, and basically just creating disorder.

Residual Haunting - A residual spirit is basically like a tape recorder playing on a loop.  They don't know you're there, or care....they are just repeating a scene from their life over and over again.