Vulcan is a prominent world in the United Federation of Planets. The term also describes natives of the planet Vulcan.
The early history of Vulcan is largely unknown. Vulcans were capable of interstellar spaceflight since at least the 9th century BC, founding a monastery at P'Jem. The key turning point of Vulcan history was the so-called "Time of Awakening", a period of civil war that nearly destroyed their civilization; the war caused a split between the followers of Surak, who remained on the planet and embraced logic, and their adversaries who fled into space.
In the 1950's the Vulcans made first contact with the Andorians. Territorial disputes and skirmishes lead to the two interstellar powers becoming bitter rivals by the mid-22nd century.
A second, minor revolution occurred in the first half of the 22nd century, when the Vulcan High Command unsuccessfully attempted to reform Vulcan society into an expansionist power. Unknown to anyone at the time, the the High Command was being manipulated covertly by Romulan agents into fighting the Andorians.
Vulcan is one of the founding member worlds of the Federation. Political and military power falls under the Vulcan High Command; however, it's structure is largely unknown.
Vulcan blood uses copper compounds to transport oxygen, resulting in them having green blood. They are physically much stronger than humans, although the gravity on Vulcan does not seem to be high compared to that of Earth.
Telepathy is a common trait among Vulcans, usually practiced in the form of the "mind meld", in which Vulcans exchange knowledge and experience through telepathic contact. A mind meld usually requires concentration and physical contact, although Vulcans can exchange more limited information remotely and even accidentally. Vulcan telepathic ability is not restricted to contact with other Vulcans and generally bypasses language barriers. Mind melds can even be performed against unwilling subjects as a form of interrogation.
Vulcans have a life expectancy of approximately 200 years.
Vulcan is one of the major worlds of the Federation. It is unclear whether there are Vulcan colonies on other planets. The pre-Federation Vulcan government had claims on a number of planets, though these were heavily contested by the Andorian Empire.
Vulcans are the originators of much of the technology used by the Federation, although it is not clear how much of this technology they invented and how much they discovered through interaction with other races. Vulcan has a defensive fleet of unknown size as well as its own intelligence service.
During the 22nd century, Vulcan was a major power in the Alpha Quadrant, but their influence is now entirely subsidiary to that of the Federation. Two Federation vessels have been known to be crewed exclusively by Vulcans, USS Intrepid in the 23rd century and USS T'Kumbra in the 24th.