Tradition has it that humans did not compose the revered compositions of the Vedas, but that God taught the Vedic hymns to the sages, who then handed them down through generations by word of mouth. Another tradition suggests that the hymns were "revealed," to the sages, who were known as the seers or “mantradrasta” of the hymns.
THE RIG VEDA
The Rig Veda is a collection of inspired songs or hymns and is a main source of information on the Rig Vedic civilization. It is the oldest book in any Indo-European language and contains the earliest form of all Sanskrit mantras, dating back to 1500 BCE- 1000 BCE. Some scholars date the Rig Veda as early as 12000 BCE - 4000 BCE.
THE YAJUR VEDA
Yajur Veda is also a liturgical collection and was made to meet the demands of a ceremonial religion. The Yajur Veda served as a practical guidebook for the priests who execute sacrificial acts while muttering simultaneously the prose prayers and the sacrificial formulae.
THE SAMA VEDA
"Sama Veda" is an ancient Hindu scripture and one of the four main Vedas of Hinduism. It is a collection of melodies and chants, and is also called the "Book of Song," "Veda of Chants" or even "Yoga of Song." It is basically the words of the "Rig Veda" put to music.
THE ATHARVA VEDA
The last of the Vedas, this is completely different from the other three Vedas and is next in importance to the Rig Veda with regard to history and sociology.
A different spirit pervades this Veda. Its hymns are of a more diverse
character than the Rig Veda and are also simpler in language.