
What is the basis of a natal chart and what is understood about an individual through it?
In astrology, a natal chart is a stylized map of the universe with the “native” (the individual or subject to be studied) at the center.
It is calculated for the exact time and location of the native’s birth for the purposes of gaining insight into the native’s personality and potential.

Commonly used alternative names for the natal chart include:
birth chart,
astral chart,
horoscope,
natus,
nativity,
radix,
geniture
and genethliac chart, among others.
The chart shows the positions of the sun, moon, planets, and potentially other celestial objects, all referred to as the native’s “planets,” within the frames of references defined by the astrological signs and houses.
Simply put, an astral cart is the snap-shot (photograph) of the positions of the native’s astral bodies exactly at his time of birth.
How do natives, with the same DOB,POB and TOB be so different?
Where DOB is date of birth, POB is Place of Birth and TOB is time of birth.
Please remember Hund’s Rule – No two electrons can have the same set of four quantum numbers.
Now understand this factor. It is impossible for 2 infants born to have exactly the same date, time and place. Maybe the date and time are exactly the same – but place – or to put the exact term -position? Unless the doctors mount 2 mothers in labor pain on top of each other…..well – even then the distance from the ground will cause the native to have different longitude and latitude!
So what about twins?
Well – Time of birth is different by minimum 1 minute!
Yes, folks such is the minute detailing required to find out exactly about the potential and personality of the native!
Coming up next::
What are the qualities of planets?
Source http://en.wikipedia.org/