The horoscope is a chart, based upon the position of the stars at the time of your birth.
This position of the stars, referred to as The Constellations is said to reflect your unique personality and characteristics. It is used sometimes to open conversation in a general way.
For example, if you tell me that you are born on the 10th of September,
I will know that you are a Virgo personality, and therefore, you will be a personality that is "analytical". If you indicate that you are a Pisces, I will understand that you tend to be emotionally sensitive. If you are a Leo, I will know that you do not easily change, but that you also have a "Queenly" demeanor like Royalty and that you are very charitable.