Astrolgy is often misspelled word for Astrology. All horoscopes are based on the position of planets in the sky at the time of an event or birth. From thereon, the differences start. There is Vedic Astrology, Western Astrology and Chinese Astrology besides others. Vedic Astrology is Sidereal, Western Astrology is Tropical whereas Chinese Astrology requires no planetary positions as such.
Vedic astrology emphasizes that time and location of an event guides its future destined evolution. Vedic astrology provides horoscope calculation methods and dasha/mahadasha system to time future events accurately.