Nakshatras importance in vedic astrology .

The Nakshatras or Star constellations
First the zodiac was divided into 12 main rasis, to study the effects of the planets placed there. Then the ancient seers added another sub divisional system of breaking down the zodiac into 27 Nakshatras or star constellations. Each nakshatra has a span of 13 degrees and 20 minutes. After that each nakshatra was further subdivided into 4 Padas, or quarters, of 3 degrees and 20 minutes. Hence the first zodiac sign Aries, which has 30 degrees, contains the entire 4 padas (13:20') of the 1st star constellation Ashwini, the entire 4 padas (13:20') of the 2nd star constellation Bharani and the 1st pada (3:20') of the third star constellation Krittika. So each rasi contains total 9 padas. These nakshatras belong to three main groups: Deva or divine, Manusha or human and Rakshasa or Demonic. They have different ruling deities, owned by different planets and have divergent qualities. Hence while studying the effects of a planet placed in Aries, it is also studied in which nakshatra it is placed and in which pada of that nakshatra it is placed. This system of analysis exists only in Indian astrology.
The nakshatra in which your moon is placed at the time of your birth is called your Janma Nakshatra. This janma nakshatra has also got its influence on you.
The following table shows the names of the 27 nakshatras in their zodiacal order.