Vedas

The Vedas are the four holiest books of the Hindu religion. 

Each book has four major kinds of text – the Samhitas (mantras and benedictions), the Aranyakas (text on rituals, ceremonies, sacrifices and symbolic-sacrifices), the Brahmanas (commentaries on rituals, ceremonies and sacrifices), and the Upanishads (texts discussing meditation, philosophy and spiritual knowledge).  The Vedas are written in Vedic Sanskrit.

Later types of Hinduism that are very different from the types of Hinduism that follow the Vedas.

The four Vedas are:

 the Rigveda
 the Yajurveda
 the Samaveda
 the Atharvaveda

Rigveda
Rigveda is the first of the four Vedas. Rigveda means a Veda of praise. This Veda has several verses (hymns).  This Veda is also the oldest Hindu holy book.

 Yajurveda 
Yajurveda is the second of the four Vedas. Yajurveda means the Veda of the Yajus. Yajus were mantras sung during religious activities. Yajurveda is divided into two parts. The name of the first part is Black Yajurveda, called Taittiriya.The Taittirīya Upanishad is a Vedic era Sanskrit text, embedded as three chapters of the Yajurveda. It is a mukhya Upanishad, and likely composed about 6th century BC. The Taittirīya Upanishad is associated with the Taittirīya school of the Yajurveda, attributed to the pupils of sage Tittiri. The name of the second part is White Yajurveda, is called Vajasaneyi.

Samaveda

Samaveda is the third Veda of the four Vedas. Samaveda means the Veda of sacred songs. This Veda also has many hymns. They were sung by the Hindu priests and other Hindus during religious activities.

Atharvaveda
Atharvaveda is the fourth of the four Vedas. Atharvaveda means the Veda of knowledge.
The Atharvaveda holds key for the massive vedic knowledge on the sciences like medicine, sorcery and has many facts that the present generation is still trying to crack.

References
 Flood, Gavin.  An Introduction to Hinduism. Cambridge University Press: Cambridge, 1996. .
 Michaels, Axel. Hinduism: Past and Present. Princeton University Press: 2004. .
Radhakrishnan, Sarvepalli;  and Moore, Charles A. A Source Book in Indian Philosophy.  Princeton University Press, 1957; Princeton paperback 12th edition, 1989. .
Walker, Benjamin Hindu World: An Encyclopedic Survey of Hinduism, (Two Volumes), Allen & Unwin, London, 1968; Praeger, New York, 1968; Munshiram Manohar Lal, New Delhi, 1983; Harper Collins, New Delhi, 1985; Rupa, New Delhi, 2005, .
Winternitz, Moriz. History of Indian Literature. Vol. 1 (of two volumes), p. 1. (Calcutta 1926)

Bibliography
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Other websites
A translation of Rig Veda 
 The Vedas at sacred-texts.com
 Vedas: Rig, Sama, Yajur, and Artharva 

Category:Hindu texts
Category:Vedas