Astrology
Astrology is the symbolic system that interprets the positions of the Sun, Moon, planets and zodiac signs at the moment of a person's birth to deduce traits of personality, life trends and compatibilities. The current Western tradition derives from Ptolemaic astrology (Claudius Ptolemy, Tetrabiblos, 2nd century AD), which formalized the tropical zodiac.
Astrology vs astronomy
The two were the same discipline until the 17th century. The scientific revolution separated them: astronomy studies celestial bodies factually; astrology attributes them symbolic meaning. The scientific consensus today treats astrology as a symbolic/cultural system, not as predictive science.