In constellations or Taramandal, there are twelve sectors of the ecliptic, the great circle. These sectors are known as Rashi or Zodiac. Each Rashi is associated with a sign. These twelve Rashi are Mesha or Aries, Vrishabha or Taurus, Mithuna or Gemini, Karka or Cancer, Simha or Leo, Kanya or Virgo, Tula or Libra, Vrishchika or Scorpio, Dhanu or Sagittarius, Makara or Capricorn, Kumbha or Aquarius and Meena or Pisces.
In simple words, Rashi means in which constellation or Nakshatra a planet is positioned. If Chandrama is positioned in Kumbha then the Chandra Rashi is Kumbha and if Surya is positioned in Makara then Surya Rashi is Makara.
Generally, Rashi refers to the Chandra Rashi or Moonsign. The Rashi or sign, in which moon was positioned at the time of the birth, is known as Rashi or Janma Rashi or Chandra Rashi. Vedic astrology gives more important to Rashi or Moon sign than Sun sign and any other single point in the Kundali.