Astrology is a group of systems, traditions, and beliefs in which knowledge of the relative positions of celestial bodies and related information is held to be useful in understanding, interpreting, and organizing knowledge about personality, human affairs, and other terrestrial events. A practitioner of astrology is called an astrologer, or, less often, an astrologist. Historically, the term mathematicus was used to denote a person proficient in astrology, astronomy, and mathematics.[1][2]