Spock is the Vulcan science officer aboard the Enterprise in Star Trek. Played most famously by Leonard Nimoy, he serves as the ship’s science officer and first officer in the original television series, working alongside Captain James T. Kirk and chief medical officer Leonard “Bones” McCoy.
Spock is notable for being half human and half Vulcan. His human mother, Amanda Grayson, and Vulcan father, Sarek, place him between two cultures. That background drives many of his stories, especially the tension between Vulcan logic and human emotion. His pointed ears, raised eyebrow, and Vulcan nerve pinch became signature elements of the franchise.
The answer is sometimes confused with McCoy, who is the Enterprise’s doctor, or Scotty, who is the chief engineer. Sulu is a helmsman and later commands his own ship. In later Star Trek stories, Spock serves on different Enterprise incarnations and holds additional roles, but the classic science-officer description most directly refers to his position under Kirk in the original series.