The zodiac is a belt of sky divided into twelve sections, each named after a constellation of stars that ancient astronomers noticed there. As Earth orbits the sun throughout the year, the sun appears to move through these twelve star patterns: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces.

Ancient civilizations, especially the Babylonians and Greeks, created the zodiac to track time and seasons. Farmers used it to know when to plant crops. Sailors used it for navigation. Because the patterns repeated reliably year after year, people could use the zodiac like a cosmic calendar.

Many people today know the zodiac through astrology, which assigns personality traits based on which constellation the sun was passing through when someone was born. If you were born in late July, for example, your zodiac sign might be Leo. While astrology remains popular in horoscopes and personality quizzes, it's important to know that astronomy (the science of studying space) and astrology (the belief that star positions affect personality) are different things. Astronomers study the actual positions and movements of stars and planets, while astrology makes claims about human behavior that scientists haven't been able to verify.