The study of the positions and aspects of celestial bodies in the belief that they have an influence on the course of natural earthly occurrences and human affairs.

The etymological origin of the word "astrology" is the Greek word αστρολογία, derived from άστρον, astron, "star" and λόγος, logos, which has a variety of meanings generally related to "systematic thought or speech". Logos is written in English as the suffix, -ology, denoting a "study or discipline".

Jyotisha is a Hindi/Sanskrit word means “light or brightness” and in plural "the heavenly bodies, planets and stars". It is one of the six disciplines of Vedanga or part of Veda. Veda means knowledge that dispels ignorance so the Jyotisha or Indian Astrology dispels darkness and illumines life by knowledge of fortunes and misfortunes. The essence is Light of Divine or eye of divine that perceives past, present and future of life in relation to entire cosmos. Jyotisha is the instructional element of the Rig Veda, and is Vedanga, or "body part" of the Vedas.

Jyotish is further divided into three skandas namely Ganita, Samhita & Hora.

• Ganita or Siddhanta: It deals with the mathematical aspect of astrology and needs proficiency in calculations.
• Samhita : It means a collection or compendium of law or code of any branch of learning like the Narada Samhita, Garga Samhita and Vashishta Samhita etc. It deals with the events, which influence the masses such as national and international happenings, weather forecasts, natural disasters, eclipses, earthquakes, cyclones, famines, epidemics, political and economic developments of nation etc.
• Hora or Jataka : It deals with natal predictive astrology for the guidance of individuals. It is that part of jyotisha which deals with the birth of a person at a given time to enjoy or suffer his Sanchita (accumulated) karmas, to fulfill his Prarabdha (the karma allowed for his incarnation) and create Agami (future) Karmas by his Kriyamaan and continued actions