A Birth Chart, also known as a Natal Chart, is the exact position of all the constellations, planets, and points at the time and place of an individual's birth. In other words, it is the snapshot of the sky, at the exact time and place of an individual's birth.
As we have discussed before, the 360-degree Zodiac represents the sky, and the sky appears to be rotating from the Earth's view point. Thus, as the sky keeps rotating, the Birth Chart of an individual is represented by the Zodiac as seen from the exact place on Earth that the individual is born at, and at the exact time of his or her birth.
In addition to the exact position of the planets in the Zodiac Signs, the exactness of character of the individual may be obtained from a Birth Chart by diagnosing the "houses" that are influenced by the planets, and the "aspects" that the planets form with each other - that are explained in the next two articles.
These positions are referred as the "Natal Positions" of the "Natal Planets" when compared with the current transiting planets and positions for predictive astrology - that is explained here
, when included with the astrologer's interpretations and predictions, is known as a "Horoscope".
For marriage, associations, and partnerships - including business and financial, the compatibility of two or more persons is diagnosed by a common chart to represent the Birth Charts of two or more individuals. This common chart is known as a Composite Chart.
A Composite Chart, thus, aid in understanding the differences of interest and influences of the present and future transits - based on the impacted "houses" and the "aspects" formed with each other.
In astrology, Sun Sign compatibility is a generic and broad understanding. The study of Composite Charts is known as Synastry, which delves into composite charts to illuminate how individuals interact and form relationships or companionships - based on the resulting interplay of energies.