Being the oldest in Vedic literature, it holds immense significance, because it is the most priceless record of ancient India. Rigveda contains 10 chapters or Mandals, 1028 Suktas or Vedic Sanskrit hymns and 10,600 verses in totality. These are invocations addressed to various Gods who are believed to possess powers of nature embodied. The Rig Veda has its own Deities, Varuna and Indra were most important deities worshipped.

There is a huge controversy among scholars concerning the time of composition of Rigveda. Prof Max Muller fixes it between 1200 B.C. to 1000 B.C., whereas, Tilak fixes it as 6000 B.C. and Prof. Jacobi in 4500 B.C. However, a general belief goes that Rig Veda, the oldest of the four Vedas and the most revered one, was composed about 1500 B.C. in the Punjab (Sapta Sindhu) region and codified about 600 B.C.

Rig Veda reflects a polytheism that is mainly concerned with the propitiation of divinities associated with the sky and the atmosphere. It is also the oldest book in Sanskrit or any Indo-European language. It was preserved in India over centuries by oral tradition alone and was probably put in writing after the early Middle Ages. While originally several different versions of the Rig Veda were said to exist, only one remains. Its form has been structured in several different ways to guarantee its authenticity and proper preservation through time.

Rig Veda is built around a science of sound, which comprehends the meaning and power of each letter. All the other Vedas are based upon it and consist to a large degree of various hymns from it. Most aspects of Vedic science like the practice of yoga, meditation, mantra and Ayurveda can be found in the Rig Veda and still use many terms that come from it. Thus, when the term Vedic is given to any layer of the Vedic teachings including the Bhagavad Gita, primarily, then it applies to the Rig Veda. Today, this text is revered by Hindus around the world, primarily in India & Nepal. Its verses are recited at prayers, religious functions and other auspicious occasions.

Rig Veda is also organised in 10 books, known as Mandalas. Each mandala consists of hymns, called Sukta, which in turn consist individual verses. The chief gods of the Rig Veda are Indra, a heroic god who is praised for having slain his enemies. Other prominent gods are Mitra-Varuna and Ushas. Also invoked are Savitar, Vishnu, Rudra, Pushan, Brihaspati, Brahmanaspati, as well as deified natural phenomena such as Dyaus Pita (the sky), Prithivi (the earth), Surya (the sun), Vayu (the wind), Apas (the waters), Parjanya (the rain), Vac (the word), the rivers like the Sapta Sindhu, and the Sarasvati River). Groups of deities are the Ashvins, Maruts, Adityas, Rbhus and the Vishvadevas. It contains various further minor gods, persons, concepts, phenomena and items, and fragmentary references to possible historical events, notably the struggle between the early Vedic people and their enemies. The details of the hymns are given as follows-

Mandala 1 comprises 191 hymns. Hymn 1.1 is addressed to Agni and his name is the first word of the Rig Veda. The remaining hymns are mainly addressed to Agni and Indra.

Mandala 2 comprises 43 hymns, mainly to Agni and Indra.

Mandala 3 comprises 62 hymns, mainly to Agni and Indra. The verse 3.62.10 has great importance in Hinduism as the Gayatri Mantra.

Mandala 4 consists of 58 hymns, mainly to Agni and Indra.

Mandala 5 comprises 87 hymns, mainly to Agni and Indra, the Visvadevas (gods of the world), the Maruts, the twin-deity Mitra-Varuna and the Asvins. Two hymns each are dedicated to Ushas (the dawn) and to Savitar.

Mandala 6 comprises 75 hymns, mainly to Agni and Indra.

Mandala 7 comprises 104 hymns, to Agni, Indra, the Visvadevas, the Maruts, Mitra-Varuna, the Asvins, Ushas, Indra-Varuna, Varuna, Vayu (the wind), two each to Sarasvati (ancient river/goddess of learning) and Vishnu, and to others.

Mandala 8 comprises 103 hymns to different gods.

Mandala 9 comprises 114 hymns, entirely devoted to Soma Pavamana, the plant of the sacred potion of the Vedic religion.

Mandala 10 comprises 191 hymns, to Agni and other gods. It contains the Nadistuti sukta which is in praise of rivers and is important for the reconstruction of the geography of the Vedic civilization and the Purusha sukta which has significance in Hindu tradition. It also contains the Nasadiya sukta (10.129), probably the most celebrated hymns in the west, which deals with creation.

With respect to its consequence, Adolf Keigi remarks, "The chief importance of Veda is not indeed in the history of literature but it lies elsewhere. It lies in the very extraordinary fullness of disclosures which this book gives to the student of Philosophy and History of Civilization". It sheds light upon the evolution of mankind, particularly in India. E. B. Cowele comments that, "The Mantra portion of Rigveda is our earliest authority for the social and religious institution of the Aryans". Prof. Smith also adds that, "It (Rigveda) points to the settled peoples, an organised society and full grown civilization".