Most of us do not know what is the difference between the Sun Sign and Rashi. And if you have visited an Astrologer recently, he probably might be talking about Ascendant or Lagna rather than Sun Sign or Rashi. Now what's ascendant ?
Talking about Sun Sign first, it's simply the sign in which your Sun is placed as per the western Astrology. Yes western astrogy is another dimension that gets added here. As per western astrology (and newspapers) Sun enters into Aries on 22nd March and remains in Aries till 21st April. Hence those born in this period call themselves Aries. Mind you when you call yourself Aries sign please keep it in mind you are following Western Astrology and not Vedic Astrology. As per Vedic Astrology Sun enters Aries on 14th April and remain in Aries untill 14th May.
Now lets see what is Rashi. Rashi is more popular terms being used in Vedic Astrology. It is the sign in which Moon is present at the time of your birth. You might be surprised when you see in which sign your Moon is present. It has nothing to do with Sun Sign you have so commonly associated with yourself.
Now what is ascendant or lagna. Ascendant is the point of horizon which is rising at the time of your birth. This simply means that, suppose at the time of your birth sign Scorpio was rising. Each sign is of 30 degrees. Suppose 12 degree of Scorpio has already risen at the exact time of your birth. Then we say your ascendant is Scorpio 12 degrees.
The significance of ascendant is that most of the astrological predictions are done keeping ascendant as reference point. You might have heard astrologers talking about various houses like 1st house , 2nd house, and so on. 7th house is for marriage. 10th house is for profession. All these houses are considered from ascendant. Hence ascendant is THE most important parameter in judging a horoscope. Thirty degrees of a sign moves across horizon in 2 hours hence ascendant changes every two hours. Here one degree is equivalent to 4 minutes. Hence if somebody is born at say 29 degree of Libra ascendant then one.has to be very careful regarding time of birth since time error of 5 min would change the lagna and hence consideration of all houses from lagna would change.
So next time if you are interested in Astrology or going to an Astrologer for horoscope reading be clear about your Sun Sign, Rashi and Ascendant. An astrologer also checks various houses keeping moon sign as reference but still ascendant remains most important parameter of a horoscope.