Zodiac:

These are group of stars. There positions are relatively fixed. 12 zodiacs represents 12 Rahshis; 12 houses. A Rashi is mathematically 30 deg. It is further sub-divided among 9 padas.

So Mesha(Aries ) has 4 padas from Ashwini, 4 padas from Bharini and 1 pada of Kritika.

Here comes the difference between the western astrology and indian astrology and most of us are not aware of about this. Commonly in India when we people talk about our SunSign we refer to Moon sign(Rashi). If someone says that I am a libran. It means her Moon is in libra.But the one, who follow the western astrology,says, I am a libran.It means her Sun is in libra. and where her Moon is? Guess works!!!