Vedic atrology uses the sidereal zodiac based on the constellations. According to the Vedic astrology, Rashis/Lagnas (Zodiac Signs) play a big role when determining the aspects on human lives. There are 27 Naskshasthras (constellations) which are used in different combinations in Vedic astrology. Those Naskshasthras were built with 12 zodiac signs, 12 houses and 9 planets. Distributing each of these 12 zociac signs in 12 houses and placing 9 planets accordingly is the way to those combinations. Actually this is done by considering where and when a person is born. So here we can have some understanding about how it is important these Zodiac Signs in Vedic astrology.
The word Zodiac literally means animals and refers to the patterns or configurations of creatures as seen in the twinkling stars at night. The Zodiac belt is the great circle around which our luminescent Sun apparently moves month by month throughout the year, transceiving the energy of those different constellational signs and thereby transmitting the celestial radiations to our Earth.
For each of these Rashis, there are Adhipathi Grahas( Load planets) which can be given as follows correspondingly. Mangala/Kuja (Mars), Shukra (Venus), Budha (Mercury), Chandra (Moon), Surya (Sun), Budha (Mercury), Shukra (Venus), Kuja (Mars), Guru (Jupiter), Shani (Saturn), Shani (Saturn), Guru (Jupiter). When it comes to consider the effect, it is important to compare the influence of planets on each Lagna (Zodiac Sign).
As mentioned in Vedic astrology the 12 Zodiac Signs are named as follows :