Astrology is a group of systems, traditions, and beliefs in which knowledge of the relative positions of celestial bodies and related details is held to be useful in understanding, interpreting, and organizing information about personality, human affairs, and other terrestrial matters.
Astrology incorporates Horoscopes, Psychic readings, numerology and tarot to shape their personality, affect their romantic relationships and predict their economic fortunes, among other divinations.
Astrology and astronomy were often indistinguishable before the modern era, with the desire for predictive and divinatory knowledge one of the primary motivating factors for astronomical observation. Astronomy began to diverge from astrology after a period of gradual separation from the Renaissance up until the 18th century. Eventually, astronomy distinguished itself as the scientific study of astronomical objects and phenomena without regard to the astrological meaning of these phenomena.
The core beliefs of astrology were prevalent in most of the ancient world and are epitomized in the Hermetic maxim "as above, so below". Tycho Brahe used a similar phrase to summarize his studies in astrology: suspiciendo despicio, "by looking up I see downward".
Most astrological traditions are based on the relative positions and movements of various real or construed celestial bodies and on the construction of implied or calculated celestial patterns as seen at the time and place of the event being studied.
The zodiac is the belt or band of constellations through which the Sun, Moon, and planets transit across the sky. Astrologers noted these constellations and so attached a particular significance to them. Over time they developed the system of twelve signs of the zodiac, based on twelve of the constellations they considered to be particularly important. The Western and Vedic zodiac signs have a common origin in the tradition of horoscopic astrology, and so are very similar in meaning. In China on the other hand, the development of the zodiac was different. Although the Chinese too have a system of twelve signs (named after animals), the Chinese zodiac refers to a pure calendrical cycle, as there are no equivalent constellations linked to it like the Western or Indian zodiacs. The common choice of twelve zodiac signs is understandable considering the interaction of the Sun and Moon was central to all forms of astrology. Twelve cycles of the Moon - the months - roughly coincide with one solar year, making twelve a natural choice.
The scientific community considers astrology as a pseudoscience or superstition as no scientific evidence has been found to support its claims, however belief in astrology remains widespread in the general public.