Astrology is a pseudoscience where some people believe the position of the planets and other heavenly bodies changes life on earth. A person who does astrology as a job is called an astrologer.
An astrologer looks at the planets' positions and tries to understand a person's character or tries to predict the future. Modern astrologers see astrology as a symbolic language. It is also seen as an art, or a kind of divination. Astrologers often say that the position of the stars help them know the future, but they can not really do it.
Astrology and astronomy started out as the same thing, but today they are very different.