It does track the planets, and it uses your birthday to derive your “sign”.
From which it derives a bunch of specious garbage - like predictions about the future, generalizations about your personality, and influences on human affairs by observable celestial objects.
It is similar to psychics, tarot card reading, palm reading and other traps for weak minds.
Astronomy is a branch of science. Nothing in common besides the use of the Greek root for “Star” in the name.