The tradition deals with two-dimensional diagrams of the heavens, or 'horoscopes', created for specific moments in time. The diagram is then used to interpret the inherent meaning underlying the alignment of celestial bodies at that moment based on a specific set of rules and guidelines. This is normally done for the moment of birth of an individual, or at the beginning of an enterprise or event, because the alignments of the heavens at that moment are thought to determine the nature of the subject in question. One of the defining characteristics of this form of astrology that makes it distinct from other traditions is the computation of the degree of the Eastern horizon rising against the backdrop of the ecliptic at the specific moment under examination, otherwise known as the ascendant. Horoscopic astrology has been the most influential and widespread form of astrology across the world, especially in Africa, India, Europe, and the Middle East, and there are several major traditions of horoscopic astrology including Indian, Hellenistic, Medieval, and most other modern Western traditions of astrology.