Astrology/astronomy is the oldest recorded science known to man. The oldest known constellations (Leo, Taurus, Scorpius) appear in cuneiform tables dating from 3000 BC, but may be older still.
Constellations are named patterns of stars. The classical constellations that populate our sky were first identified in the Middle East thousands of years ago. They were passed to the ancient Greeks, who imposed their own mythology and codified them in story and verse.
The most well-known single star may be Polaris ("the pole star") in Ursa Minor. The name for Polaris comes from its position nearly in a direct line with the axis of the Earth's rotation "above" the North Pole - so that it appears motionless from the Earth, and all the stars of the Northern sky appear to rotate around it.