The Zodiac is a nonexistent ring in the sky which encloses our nearby planetary group like a support. To decide the positions of the planets on this circle we require some reference point, a point which will stay settled while the eminent bodies continue moving.
The diviners of Vedic Astrology took a faraway star which stays stationary and the position of the planets was controlled by alluding them to this settled star group. This is known as the sidereal framework. Sidereal means measured by stars. The altered star group decided for the design is taken as the first level of Aries, the beginning stage of the Indian Zodiac.
The Western framework likewise utilizes a settled reference point however uses the equinoxes for the reason. Curiously, first level of Aries is once more the beginning stage of the Western Zodiac. Yet, the significant distinction is that the position of the Sun on Vernal equinox (the primary day of spring) is taken as the first level of Aries. This works similarly well on the grounds that the Sun moves 360° in a year. This is known as the Tropical Zodiac.
Taking two diverse reference focuses does not make one framework substantial and the other invalid. Truth be told, one can be numerically reasoned from the other. Old Indians knew about this. They realized that, in view of the ceaseless titling of the earth the equinoxes moved around 1° in at regular intervals. Thus, they presented the possibility of "Ayanamsha" to suit the parade of the equinoxes (Ayanchalan).
Thus, the Western Tropical Zodiac is called "Sayan" (with Ayan) i.e., with the parade of equinoxes and the Sidereal Zodiac is called "Nirayan" (without Ayan) where this is overlooked.
The planets and the houses in both frameworks are the same. There are a few contrasts in methodology. For instance, in Indian Astrology the most imperative reference point in a Horoscope is the first house known as Ascendant while in the Western System the Sun possesses the focal spot.