It tells us many things abbout the moon, sun, and stars. For example, islamic

astronomy taught us a lot about lunar positioning.

Medicine, Astronomy, Math, & Science.

Many contributions were made by Chinese and Islamic astronomers to modern day astronomy, including the trigonometric methods created to determine the precision of dates, and supernova research.

They contributed to algebra, astrology and to the field of medicine. Also, major contributions to astronomy and philosophy.

They are many in astronomy, medicine, physics, mathematics, biology, .... refer to related question and link below.