astrology and astronomy

I thought and it may be me being thick again, but I thought that
astronomy was the study of stars/planets space etc and astrology was
to do with the stars for horoscope purposes and your fate etc. If
this is not so can someone explain what the difference is please.
It's just that when reading a few peoples letters they say astrology
when I would have thought they meant astronomy.
The thing is I am ginger and sometimes that's worse than blonde -
trust me!

thanx

suzie b