Nakshatras are Lunar mansions or constellations which divide the 360 degree zodiac into 27 parts of 13 degrees and 20 minutes. Each Nakshatra is named after the prominent star in that constellation. So, we have 12 Rashis (Zodiac signs) and 27 Nakshatras. Each Rashi is of 30 degrees. The first Nakshatra is Ashwini which begins at zero degree of the first Rahsi, Mesh (Aries).

Each Nakshatra is further divided into 4 parts which are called Padas or Charans. In all, there are 108 padas of 3 degrees and 20 minutes each. Interestingly, one charan corresponds with one Navamsa. A Navamsa is the 9th division of a Rashi. So, each Rashi has 9 Navamsas and, therefore, 9 padas of Nakshatras. 

The Nakshatras are as follows -

1. Ashwini

2. Bharani

3. Krittika

4. Rohini

5. Mrigshira

6. Ardra

7. Punarvasu

8. Pushya

9. Ashlesha

10. Magha

11. Poorvafalguni

12. Uttarfalguni

13. Hasta

14. Chitra

15. Swati

16. Vishakha

17. Anuradha

18. Jyestha

19. Mool

20. Poorvashada

21. Uttarashada

22. Shravan

23. Dhanishtha

24. Shatbisha

25. Poorvabhadrapad

26. Uttarabhadrapad

27. Revati

Nakshatra are classified by their nature (Dev, Manushya or Rakshas), caste (Varna), colour, gender, virtues etc. In the traditional match-making the Nakshatras of the Moon in both horoscopes are matched to calculate the Guna Score.This Nakshatra of the Moon is called the Janma Nakshatra. This Janma Nakshatra is also the basis of calculation of the dasha periods which govern a person's life.