Vast sections of the Vedas give a detailed description of all fields of knowledge, which people may require:
Town Planning – Vastushastra
Architecture – Sthapatyaveda
Grammar – Vyakarana-Vedangas
Mathematics – Shulba Sutra
Astronomy and astrology – Jyotisha-shastra
Chemistry – Rasayana Shastra
Medicine – Ayur-Veda
Martial arts – Dhanur-Veda
Politics and law – Manu Samhita
Civil laws – Niti-shastra
Etymology – Nirukta-Vedanga
Philosophy – the Upanishads, the Vedanta-sutra
And logic, sociology, psychology, history and more.
But the most sacred part of the Vedas – is the sublime science of body, mind and soul – Divya-gyana or Atma tattva . In this area “Vedanta-sutra”, “Bhagavad Gita” and “Bhagavata Purana” are the most important.
The Vedas say that the purpose of human life is to achieve an eternal happiness, realizing oneself as a spiritual soul. The science of the soul is described in detail in the “Bhagavad-gita.”