'Tis the season of believing every bump in the night is proof of ghostly activity. You may not feel very professional looking for ghosts in your closet at 3 a.m., but paranormal investigations are serious business. They’ve become so widespread that the industry has its own lingo—and there’s nothing stopping amateur ghost hunters from learning it. Whether you plan to binge-watch your favorite ghost-hunting show or embark on your own paranormal investigation, these are the terms you should know.

1. Orb

If you’ve ever noticed a shiny, pale circle floating in your photograph, you’ve captured what paranormal investigators say is evidence of the afterlife. The orbs that sometimes show up in pictures are believed by some to be the spirits of the dead. Another explanation is that they’re specks of dust illuminated by the camera’s flash.

2. Anomaly

An anomaly is something unexplainable—i.e. many things attributed to paranormal phenomena.

3. Haunting

A haunting is a concentration of reported paranormal activity attached to a specific person or place.

4. EMF

EMF stands for "electromagnetic field." Some paranormal investigators believe ghosts disrupt electromagnetic fields or emit electromagnetic waves themselves. An EMF meter can be used to detect such energy.

5. Ghost Box

A ghost box describes any device that supposedly allows spirits to communicate verbally through technology. Some tools scan radio frequencies, occasionally catching snippets of speech that could be interpreted as the disembodied voices of the deceased. The Ovilus puts an arguably creepier spin on this concept. When it senses environmental fluctuations or EMF disturbances, the gadget translates them to “words” (or more accurately, noises) spoken in a robotic voice.

6. Physical Manipulation

Evidence of spirits altering the material realm is called physical manipulation. This could be anything from a ghost creaking open a door to one tossing a chair across the room.

7. Cold Spot

A cold spot is an area where the temperature drops in a supposedly haunted location. Ghost hunters often cite patches of cool air as evidence of ghostly activity.

8. Apparition

An apparition is a manifestation of a spirit that can be perceived by the senses. Though apparitions are often thought of as visual phenomena, they can be heard, smelled, and felt as well.

9. EVP

EVP is short for "electronic voice phenomena." Unexplained, disembodied voices that are captured using ghost boxes or picked up spontaneously on voice recorders are considered EVPs.

10. Manifestation

The physical, sensory evidence of paranormal activity is thought of as a ghostly manifestation. Physical manipulation, apparitions, and EVPs all fall under this category.

11. Entity

Entity is a vague term that can be applied to any distinct being. In paranormal investigations, the label is often given to the ghosts haunting an area.

12. Medium

A medium purports to use their psychic abilities to contact and communicate with spirits—whether they’ve crossed over into a different realm or they’re still haunting our world.

13. Psi

Psi is a shorter way to say “psychic phenomena.” Examples of psychic phenomena include communicating with others psychically (telepathy), moving objects with the mind (telekinesis), and seeing the future (precognition).

14. Clearing

Clearing is the process of purging a location of its ghostly entities.This may be the goal of a medium or ghost hunter when they’re investigating a haunting.

15. Shadow Person

A shadow person can be a type of ghostly manifestation. It describes the black, mysterious figures some witnesses report seeing out of the corners of their eyes.