Bhagavad Gita is knowledge of five basic truths and the relationship of each truth to the other: These five truths are Krishna, or God, the individual soul, the material world, action in this world, and time. The Gita lucidly explains the nature of consciousness, the self, and the universe. It is the essence of India's spiritual wisdom.

Bhagavad Gita, is a part of the 5th Veda (written by Vedavyasa - ancient Indian saint) and Indian Epic - Mahabharata. It was narrated for the first time in the battle of Kurukshetra, by Lord Krishna to Arjun.

The Bhagavad Gita, also referred to as Gita, is a 700–verse Dharmic scripture that is part of the ancient Sanskrit epic Mahabharata. This scripture contains a conversation between Pandava prince Arjuna and his guide Krishna on a variety of philosophical issues.

Faced with a fratricidal war, a despondent Arjuna turns to his charioteer Krishna for counsel on the battlefield. Krishna, through the course of the Bhagavad Gita, imparts to Arjuna wisdom, the path to devotion, and the doctrine of selfless action. The Bhagavad Gita upholds the essence and the philosophical tradition of the Upanishads. However, unlike the rigorous monism of the Upanishads, the Bhagavad Gita also integrates dualism and theism.

Numerous commentaries have been written on the Bhagavad Gita with widely differing views on the essentials, beginning with Adi Sankara's commentary on the Bhagavad Gita in the eighth century CE. Commentators see the setting of the Bhagavad Gita in a battlefield as an allegory for the ethical and moral struggles of the human life. The Bhagavad Gita's call for selfless action inspired many leaders of the Indian independence movement including Mohandas Karamchand Gandhi, who referred to the Bhagavad Gita as his "spiritual dictionary".
More commentaries have been written upon the Gita than upon any other philosophical or religious text in history. As a classic of timeless wisdom,
it is the main literary support for the oldest surviving spiritual culture in the world-that of India's Vedic civilization. Not only has the Gita directed the religious life of many centuries of Hindus, but, owing to the pervasive influence of religious concepts in Vedic civilization,
the Gita has shaped India's social, ethical, cultural and even political life as well. Attesting to India's nearly universal acceptance of the Gita, practically every sectarian cult and school of Hindu thought, representing a vast spectrum of religious and philosophical views,
accepts Bhagavad-gita as the summum bonum guide to spiritual truth. The Gita, therefore, more than any other single historical source, provides penetrating insight into the metaphysical and psychological foundation of India's Vedic culture, both ancient and contemporary.
भगवत्‌ गीता

महाभारत युद्ध आरम्भ होने के ठीक पहले भगवान श्रीकृष्ण ने अर्जुन को जो उपदेश दिया वह श्रीमद्भगवद्गीता के नाम से प्रसिद्ध है। यह महाभारत के भीष्मपर्व का अंग है। गीता में 18 अध्याय और 700 श्लोक हैं।[1]आज से (सन 2022) लगभग 5560 वर्ष पहले गीता जी का ज्ञान बोला गया था। गीता की गणना प्रस्थानत्रयी में की जाती है, जिसमें उपनिषद् और ब्रह्मसूत्र भी सम्मिलित हैं। अतएव भारतीय परम्परा के अनुसार गीता का स्थान वही है जो उपनिषद् और धर्मसूत्रों का है। उपनिषदों को गौ (गाय) और गीता को उसका दुग्ध कहा गया है। इसका तात्पर्य यह है कि उपनिषदों की जो अध्यात्म विद्या थी, उसको गीता सर्वांश में स्वीकार करती है। उपनिषदों की अनेक विद्याएँ गीता में हैं। जैसे, संसार के स्वरूप के संबंध में अश्वत्थ विद्या, अनादि अजन्मा ब्रह्म के विषय में अव्ययपुरुष विद्या, परा प्रकृति या जीव के विषय में अक्षरपुरुष विद्या और अपरा प्रकृति या भौतिक जगत के विषय में क्षरपुरुष विद्या। इस प्रकार वेदों के ब्रह्मवाद और उपनिषदों के अध्यात्म, इन दोनों की विशिष्ट सामग्री गीता में संनिविष्ट है। उसे ही पुष्पिका के शब्दों में ब्रह्मविद्या कहा गया है।[2]
श्री कृष्ण के इन्हीं उपदेशों को “भगवत गीता” नामक ग्रंथ में संकलित किया गया है।