The word Veda means knowledge. Vedas are considered to be Shruti means what is heard literature. It is believed that, sages (Rishis) heard the Veda hymns that are coming from Universe (Brahmand). There are four Vedas: Rigveda, Yajurveda, Samaveda and the Atharvaveda. Each Veda has been sub-classified into four major text types – the Samhitas (collections), the Brahmanas (ritual hymns), Aranyakas (discussion of symbolic meta-rituals, as well as philosophical speculations), and the Upanishads (text discussing meditation, philosophy and spiritual knowledge).

In the Vedic period, the Vedas was transmitted orally across generations, preserved with precision with the help of elaborate mnemonic techniques. A literary tradition is traceable in post-Vedic times, after the rise of Buddhism. Due to the ephemeral nature of the manuscript material, surviving manuscripts rarely surpass an age of a few hundred years. The various oriental philosophies, orthodox, heterodox or non-orthodox did not regard the Vedas as their origin. Despite their differences, the Vedas discuss similar ideas and concepts.

Rigveda

This is the oldest, an extant literature of philosophy, is a collection of 1,028 hymns approx., organized into ten Mandalas (books). The hymns discuss about betterment, philosophy, belief, rationality, duties, service and others. Some verses of Rigveda continue to recite during rites, celebrations such as weddings and prayers, making it the world's oldest religious text.

The Rigvedic hymns are dedicated to various deities. It contains the Nadistuti Sukta, which is in praise of rivers and is important for the reconstruction of the geography of the Vedic civilization. The Purusha Sukta, which is important in studies of sociology. It also contains the Nasadiya Sukta, the collection of hymns on non-Eternity and deals with the origin of universe.

Yajurveda

Yajurveda is prose mantras of knowledge. Yajurvedic verses are of religious reverence and used in rituals. The hymns discuss about knowledge of courage, resoluteness, service, social responsibilities, philosophy & others. The Yajurveda Samhita includes about 1,875 verses approximately and is broadly grouped into Krishna Yajurveda and Shukla Yajurveda.

Yajurveda Samhita includes collection of primary Upanishads. These include the Brihadaranyaka Upanishad, the Isha Upanishad, the Taittiriya Upanishad, the Katha Upanishad, the Shvetashvatara Upanishad and the Maitri Upanishad.

Samaveda

This is the Veda of melodies and chants. This collection of hymns discusses about knowledge of art, plays, music, entertainment, psychology, philosophy and others. The Chandogya Upanishad and the Kena Upanishad, two primary Upanishads are embedded inside the Samaveda.

The Indian classical music and dance is rooted in the sonic and musical dimensions of the Sama Veda, along with the Upanishads. The Samaveda, in addition to singing and chanting, mentions about instruments. The Gandharva Veda, a Upveda (Sub-Veda) in Samaveda is a set of rules and suggestions for playing various instruments. The structure and theory of chants in the Samaveda have inspired the organizing principle for Indian classical arts and performances.

Atharvaveda

The Atharvaveda is a collection of 20 khandas (books), with a total of 730 hymns. The Atharvaveda Samhita originally was organized into 18 khandas (books), and the last two were added later. The hymns include knowledge of health, wealth, trade, commerce, property, stability, philosophy & other.

The Atharvaveda includes mantras and verses for treating a variety of ailments. Paippalada Atharvaveda discusses about medical conditions. The hymns are prayers and incantations wishing of become healthy. Several hymns in the Atharvaveda are praise of medicinal herbs and plants, suggesting the medical and health value of plants and herbs.