Jyotiṣa or Vedic Astrology is the science of the study of time and space. This science of Jyotiṣa is the understanding of the effect of time and space on the entire life and activities of the earth. Time is Kāla and Ākāśa.
This study revolves around the two principle luminaries viz., the Sun (Sūrya) and the Moon (Candra). This ancient study of Vedic astrology known as Jyotiṣa. The word Jyotiṣa comes from Jyoti and Īṣa which is the study of light. Jyotiṣa is the study of Jyoti meaning light which comes naturally from the Sun. This ancient science of Jyotiṣa comprises of three major branches viz,
(i) Hora Shastra – the study of time. The word “Hora” has been derived from two words – “Aho” meaning day and “Ratra” meaning night;
(ii) Ganita Shastra – the study of the mathematical part of astrology and astronomy;
(iii) Gola Shastra – the study of astronomy, which included observation and analysis of stellar effects and the effects of the motion of planets in the solar system.
The forth which is also very important is Samhita. This study related to the Mundane affairs of nations, earthquakes, weather patterns, economic trends, etc.