EVP - EVP stands for "Electronic Voice Phenomena". The theory is that spirits talk on a decibel level that is out of human range. Voice recorders, however, are able to pick up this frequency. This is why paranormal investigators use voice recorders to talk to a spirit.
EMF - EMF stands for "Electromagnetic Frequency". Some also use the term "Electromagnetic Force or Field". Electricians use EMF Meters to determine if a wiring job is good because it this device picks up on energy currents that are moving through the air. Spirits give off energy and are basically energy. Therefore, paranormal investigators use this device to detect the energy of possible spirits. If you are getting a reading and there is nothing in the room that is man-made that is giving off the reading, you could be looking at a possible spirit.
Pareidolia or Matrixing - The eyes natural tendency to pick out random shapes or objects in photographs, video, or with the naked eye and see a face that isn't actually there.
Apparition - The appearance of a spirit. It could be a floating head, a shadow. Basically, when a spirit shows any part of itself to you, it's called an apparition. A spirit showing its full sense is what we call a full body apparition.
Aura - You may have heard this term before if you take an interest in the paranormal. This is a very common term when it comes to psychic abilities. Think of it as another word for your soul. An aura is your own energy that surrounds your body.
Cold and Warm Spots - Everything around us is energy. Temperature is reactive to energy. When a spirit manipulates the energy around it, the temperature may change by either rising or falling. This is a reaction to the change of energy in the atmosphere.
Manifest - This term is similar to the term "apparition" but it covers a more broader aspect. An apparition is when a spirit is showing you its actual self. Manifesting is when a spirit is appearing to you in general, whether it be a simple orb or a full blown apparition.