Vulcans hail from a planet with the same name, Vulcan. You could say that Vulcans are space elves as they have the same ear characteristics as elves, pointy ears. Vulcans have learned to do away with emotion and instead rely on logic and follow the teachings of Surak. Vulcans are capable of emotions but to do so would show their weakness. Vulcans appear working alongside humans aboard numerous crafts. They appear in the original series (Mr. Spock), Voyager (Tuvok) and Enterprise (T`Pol as one of the main crew members. A Vulcan ship was the first alien race that Zephram Cochrane met after his first journey into space. From the moment of `First Contact` to the "current", Vulcans have always been friends.
Vulcans have a sister race, the Romulans who are Vulcans who left the planet and have a different philosophy that they follow. The Vulcans try to make amends with the Romulans with Mr Spock leading an undercover group in the twin episdes called Unification - Part 1.
Vulcans are able to read minds (mind melds) when they touch the targets face. Spock did a mind meld on Dr. McCoy before Spock stepped into the radiation chamber to save the USS Enterprise NCC-1701A from being destoyed by the exploding Khan ship in `Vulcans can disable a person by touching their necks.