Clairvoyance, based on a 17th Century term that means clear vision, is a type of ESP - Extra Sensory Perception. Although usually used to describe a number of psychic abilities, for example second sight, telepathy, prophetic ideas and psychic dreams, it is strictly speaking the power to discern details about a person, object, place or event via perception other than from the usual five senses. A person gifted with this ability is called a clairvoyant - a person who sees clearly.
In parapsychology, the term clairvoyance is used purely to describe information - in the the present time and not necessarily readily accessible to the particular clairvoyant - coming from an external source, rather than telepathy, where information is moved from one mind to another. In other words, a email has the ability to see or even visualise events, things or persons away from capability or selection of physical sight.
Remote control viewing, usually a managed, specific process, can be a facet of voyance telephone, as is email dreaming. For instance, you might dream about a location they've never seen before and later on find it is exactly as they had visualised it in their dream.
This happened to me, for example, after i was about to start my first term in school. As I had never frequented the city where the college was located, my Father offered to take myself there in order to find the way in which from the train station to the college. Having dreamed about it the night before we went, I used to be able to lead him to the school along the shortest course possible, knowing in which and when to turn. I was even able to make sure he understands how long it would take us to get presently there.
However, outside of the industry of parapsychology the term is frequently used to describe other sorts of paranormal, or anomalous, perception. Generally, it is used in regards to the perception of earlier (retro cognition) or perhaps future (precognition) events. It is a gift many have got without even realising that. To use another knowledge as an example (and I usually do not claim to be a email in any way), a few years ago, the friend's daughter choose to go into hospital early in the evening to have her first child. Although with a group of shared friends around 10 PM, someone suggested we should call the hospital and find out exactly how she was making. As one of them picked up the phone, I declared that a call could be wasted, as she would have a little boy during the early hours of the following morning. We called anyway and were advised she was asleep as the labour experienced slowed. My friend said the next morning that her grandson was created at 5:30 AM.
Frequently, sources will also refer to the perception of images perceived during communication together with spirits as clairvoyance.
In any case, clairvoyance is a precious gift which can and should be used in order to help and guide others.