Real vampires are people who need, not just desire, regular intake of either blood or life energy. Without feeding, vampires tend to feel "under the weather", irritable, and have physical side effects that only subside after feeding. Vampires also usually have varying degrees of psychic/psi abilities and enhanced senses. They heal a bit faster and tend to be stronger, faster and have quicker reflexes than average people. This is not to say that they have any thing that would be considered superhuman or extreme.
Sanguinarians are vampires who feed on blood. Whether they feed on human blood, animal blood or rare meat they fall into this category. They are also called sangs, sanguine or sanguin for short.
Psi vampires feed on energy rather than on blood although some do feed from the energy that is concentrated in blood. This energy is sometimes called psi, prana, chi or even simply life force and is in almost everything around us. A psi vampire can feed on this energy in various ways. Some use direct contact with a donor while others feed off the ambient energy or emotional energy generated in crowds or from a sexual encounter. Still others feed off of the energy in weather, the earth itself or a basic element such as water, wind or fire. Because of the various methods of feeding often psi vamps are referred to by various other names such as psychic vampire, pranic vampire or an assortment of other names, each referring to the method of feeding they use. Vampires that can feed on either blood or energy are considered hybrid vampires.
Some sang vamps adamantly declare that only sanguinarians are the real vampires, that there are no other real vampires. In addition many psi vampires insist that all vampires feed off of energy and that sang vamps are simply feeding off of the energy concentrated in the blood. Personally I am a sang vamp and some of my friends are psi vamps while others are sang vamps. A few of my psi vamp friends convinced me to try feeding on energy from other sources than blood. I tried and although I was quite adept at drawing and manipulating energy, it was not the same for me. Feeding on energy did diminish my immediate need but did not completely abate the need to feed.
To simplify this let me state that regardless of the manner in which we feed and since we all experience similar effects when we are unable to feed then we all should simply refer to ourselves as vampires.