"The placement of the celestial bodies in the heavens at any given moment in time reflects the nature of that moment, including the nature of an individual born in that moment."
Astrology is the study of the positions and aspects of celestial bodies in the belief that they have an influence on the course of natural earthly occurrences and human affairs. Astrology in one form or another was around even before mankind's earliest written records began. There are many traditions of astrology because each part of the world had it's own form and method of looking at the stars for information and assistance.
Astrology can be used as a form of divination by anyone who is willing to learn the basics and apply them. Many modern astrologers define astrology as an art form or a symbolic language. Some individuals in the mainstream scientific community still consider astrology a pseudoscience or even superstition. But Astrology has played a role in the shaping of culture, early astronomy, and other disciplines throughout history.
As early as about 5000 B.C.E (before Christ/before common era), the Sun, Moon, and Stars were an important focus of many early civilizations. Most systems of astrology share some similar features. Before the modern era, the science of Astronomy was often indistinguishable from Astrology. Both involved the observation and study of the motions of celestial objects in order to make predictions.
Zodiac is actually the belt or band of constellations through which the Sun, Moon, and planets transit across the sky. Early astrological observation of the most important constellations developed over time into the twelve signs of the zodiac now know as: Aries, Taurus, Gemini, Cancer, Leo , Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces.
Each calendar year is divided into twelve months of around thirty days each. Each thirty day period is associated with a section of the zodiac, and with one of the twelve zodiac signs. The Sun (which can actually be considered a planet in astrology) takes about thirty days to travel through each of the twelve astrological signs. Your Sun Sign is derived from the section of the Zodiac (the sign) where the Sun was placed at the time of your birth. It's easy to find of course because all you need to know is your month and day of birth.