Astrology is based on the belief that the alignment of stars and planets influences life on Earth. Astrologers use the positions of the planets, stars, sun, and moon to interpret the past, present, and future. They use complex calculations to analyse the positions of the planets at the time of an individual's birth to create a birth chart, also known as a natal chart. This chart is used to predict the future and understand a person's personality, strengths and weaknesses.