Psychic ability is in fact a form of ESP. There are 4 main forms and they are telepathy, which is the ability to communicate information through thoughts. An individual can perceive another's thought and send thoughts to another person. Clairvoyance is the ability to sense an event or object in another place or time. One example is the perception that a friend's house is on fire. Precognition is the ability to see future events.
Psychokinesis is the ability to control an object with the mind. clairvoyance is the power to perceive objects that are not accessible to the senses, this is sometimes called clear sight and it is this ability that shows itself as images within the minds eye. If you think of an orange, what it looks like, the texture, the peel, the centre of the orange, you use your imagination to see this in your minds eye. Psychics see like this, only they are seeing images that are put there by spiritual beings.
They could be your spirit guides, their spirit guides, angels who have called in to help, or guides who have never incarnated as human, but who like to help out on the earth plane. So clairyoyance is also part of mediumship as the deceased spirit uses this channel to communicate with them. Telepathy is mind to mind communicaton. So in essence, when you are having a psychic reading and something is on your mind, then these emotions will sit in your energy field also known as an aura, this can be read by the reader.
The other way they can pick up information is by reading your mind. For example, if a pet is lost then a pet psychic will ask the caller or face to face client to imagine the pets face and image. The psychic will then link into this using telepathy. Then, using remote viewing which is a form of clairvoyance the psychic will often see an image of where the pet has been lost. There have been some very very accurate descriptions of this type, where the owners have been able to go and retrieve the pet based on the information given by the reader, this is a very real and very useful service one person who has the ability can offer another.
In the same way a psychic reader can link into a person when the client has been asked to imagine their face, and so help out with interpersonal issues as they can also read the energy of the clients partner in addition to the energy of the client. So you can see ESP has a very real and useful place in society. Those people who have the gift are using their right brain ability, when most of us use our left brain ability. It is the opinion of many spiritual gurus, philosophers and teachers, that this world is in a mode of change and that a re-birth of sorts is taking place.