1. Different astrological signs accession dates.
2. Western astrology use Zodiac of astrological signs. Vedic astrology use Zodiac of constellations.
3. Vedic astrology is the world's most common astrology. India is the second largest country in the world by population. There are many Vedic astrologers and Vedic astrologers operate outside of the India too.
4. Vedic astrology is a part of large philosophical system - Vedas. Vedic astrology principles are embedded in Vastu, Ayurveda.
5. Vedic astrology uses the Sun, Moon, Venus, Jupiter, Saturn, Mars, like Western astrology. The classical Vedic astrology does not take into account the slow with the naked eye invisible planets (Uranus, Neptune, Pluto). Vedic astrology include in their analysis Rahu and Ketu (North and South Moon nodes), in contrast to Western astrology.
6. Vedic Astrology Gives the Moon and the Ascendent more importance than the Sun in Western Astrology. Western astrology determine human psychological types guided by the position of the sun at birth (this people call my zodiac), but Vedic astrology uses the Moon and the ascendent (lagna) for determination persons psychological typ.
7. Both systems divide zodiac into 12 parts. The names of the astrological signs are similar, but determination of the location of astrological sign is different. Western astrology uses the tropical (moving) zodiac. The beginning of the zodiac in Western astrology is place of the Sun in the constellation of Aries 0 °. Vedic astrology uses Sidereal zodiac, which is based on a real location of the constellations.
8. The spring equinox moment, as practice shows, a continuous shift on the sidereal zodiac background, at a rate of about 1 degree in 72 years, as the Earth axis by rotating create the cone. So the beginning of Spring in 1900 was at point X, in 2044, the beginning of spring, already is 2 degrees earlier. This is called precession. Therefore, unlike most tropical astrology (prevailing in the West) Vedic Astrology has chosen a more stable reference point than the beginning of spring. This is called sidereal zodiac, where the beginning of the spring is attached to the the real situation of the stars. Constellations in Vedic and the tropical zodiac has deviation (now in about 24 degrees). This deviation is called ayanamsha.
9. Vedic astrology see influence of the aspects differently than Western astrology. In Vedic astrology, the quality and strength of planets (Grahas) is more important as explanation of aspect themselves.
10. Vedic astrology also analyze planetary Yogas - the planetary combinations. There are hundreds of such combinations.
11. In addition to the 12 signs of the zodiac, Vedic astrology use 27 Moon Signs - Nakshatra. Nakshatra is a subtle Star division, which does not exist in Western astrology.
12. Vedic astrology analyze influence of planetary cycle (Dasha) effects on human life.
13. Vedic astrology not only record the situation, determines the result of karma, but gives a solution to a real improvement of life quality.
14. Vedic astrology, compared with the Western system is ancient and more complex method.