The planet Vulcan orbits a red giant star relatively close to the Sol system. The climate is generally harsh, with much of the surface consisting of large deserts or mountain ranges. Vulcan is considerably larger than Earth and has both a higher gravity and thinner atmosphere. This gives Vulcans considerably more inherent strength than Humans, especially when in the relatively oxygen-rich atmosphere most other humanoid species regard as standard. While externally similar to Humans, Vulcan anatomy differs radically; Vulcan blood is distinctly green in colour. It is pumped by a heart which occupies roughly the same location as the Human liver and is capable of beating at several hundred beats per minute. Vulcans have very sensitive ears, and their eyes have an inner eyelid which has evolved as a defence against the harsh Vulcan sun.

Perhaps the most interesting aspect of the Vulcan physiology is the brain. The Vulcan brain is in direct control of most of the bodily functions, acting as a control unit for many organs. Vulcans have learned to gain concious control of many of these functions, allowing them to regulate their bodies to a high degree by simple willpower. When injured a Vulcan can go into a trance-like state, using this ability to concentrate all of his or her energy onto repairing the injury. Most Vulcans also have almost complete control of automatic responses such as generated by intense pain. The Vulcan immune system is highly developed and enables them to resist most known forms of infection or illness.

Of course the most famous aspect of the Vulcan brain is the inherent telepathic ability. Almost all Vulcans are natural touch-telepaths, though considerable training is required to utilise this ability fully. Stronger minds are capable of non-contact telepathy, usually over short distances and in a limited fashion; occasionally Vulcans have emerged whos telepathic abilities are far stronger than the norm. The rigorous mental training all Vulcans are given often allows such individuals to develop such abilities as emotional compulsion and psychic image projection.

Culturally one of the most fascinating species in the Alpha Quadrant, the Vulcans were once an extremely violent and emotive people who waged almost constant warfare on one another. As their level of technology improved, the Vulcans eventually reached a point where their violent nature threatened species extinction. In an effort to avoid this fate, a Vulcan named Surak developed a new philosophy; Surak maintained that the root cause of all the problems on Vulcan lay in the uncontrolled outpouring of the peoples emotions. His followers swore to live their lives by an ethical system devised devised by Surak and based purely on logical principles. All expression of emotions was completely forbidden, negative or otherwise. Although this new philosophy spread rapidly across Vulcan, a minority rejected Suraks ideals. However, it was obvious that open warfare between the two factions would result in the very destruction that Surak predicted. Those who rejected Surak therefore chose to leave Vulcan and found colonies elsewhere. Most of these settled on the planets of the Romulan system, eventually founding the Romulan Empire.

The first of the current powers to discover warp drive, the Vulcans conducted a series of survey missions in the mid 2000's. First Contact between Vulcans and Humans came in 2063 when a Vulcan survey ship detected the warp flight of Zephram Cochrane. The Vulcans met with Cochrane at his launch site on the day following the flight, and a strong relationship was quickly built up between the two species. When the Humans entered into war with the Romulan Empire the Vulcans declared themselves neutral because of their pacifist principles. Once the war was over the Vulcans proposed that a solid alliance be formed between themselves and the Humans in order to deter future agression and so avoid further conflict. This United Federation of Planets was agreed in 2161, with Vulcan and Earth as the founding members.

Today Vulcan remains one of the principal Federation members, and is deeply involved in all levels of that society. Despite the enmity between the Federation and the Romulan Empire, Vulcans have been attempting to forge a more cordial relationship with their cousins - ultimately hoping to reunify the two cultures. So far these efforts have met with little success.