Back in ancient times they created constellations to navigate or tell time. The Big and Little Dipper can act like the hands of a clock. The constellations helped them understand which way they were going at sea. This was a time before compasses, and other nautical devices.
88 modern constellations - a list of the current constellations. Former constellations - a list of former constellations. Chinese constellations List of Nakshatras - sectors along the moon's ecliptic Asterism (astronomy)