The sacred Hindu texts, Collectively referred to as the Shastras, has two types of sacred writings in the Hindu scriptures: Shruti (heard) and Smriti (memorized).
*Sruti literature refers to the habit of ancient Hindu saints who led a solitary life in the woods, where they developed a consciousness that enabled them to 'hear' or cognize the truths of the universe. Sruti literatures are of two parts: the Vedas and the Upanishads.
The word Veda came out from the word vid that means knowledge. When it is applied to scripture, it signifies a book of knowledge. They are the foundational scriptures of the Hindus. vedas are believed to be the most ancient books that have mantras in them.And it is believed that no human has created them and they were created by God himself. The Vedas are the eternal truths revealed by God to the great ancient Rishis of India. Rishi means the seer i.e the one who sees, seer of Mantra or thought. The thought was not his own. The Rishis saw the truths or heard them. Therefore, the Vedas are what are heard (Sruti). He was the seer of thought which existed already. He was only the spiritual discoverer of the thought, and not the inventor. So Vedas were never written, never created. They are eternal and impersonal.
The most ancient veda is Rig veda then Samveda, Yajurveda and the least is Atharva veda..
Initially Atharva veda wasnt considered as a part of vedas. And it was believed that there are only three vedas. But later on its was accepted as a part of vedas, and formed chatur veda.
All vedas are considered to have mantras that are used to perform ceremonies and rituals. since the oldest is Rig veda so it has got all the mantras and all other vedas have more or less repetitions of the mantras that are written in Rig veda. So Rig veda is the base of all the other vedas.
(1) Rig Veda have all the mantras in them, which are used to perform rituals. its is the oldest veda.
(2) Sama Veda all the mantras that are written in Rig veda are repeated but in a poetic manner. a tune has been given to mantras in sama veda
(3) Yajurveda has also got some repetetion of mantras that are in Rig veda.. and apart from that it has some additional mantras for performing yagya and bali.
(4) Atharva Veda- again Atharva veda also has some mantras of Rig veda.. But in addition to that it has got mantras for voodoo.
As per hindu relegion Mantra-Samhitas, the Brahmanas, the Aranyakas, and the Upanishads are combinely called vedas. i.e vedas are divided into 4 parts. The division of the Vedas into four parts is to suit the four stages in a man's life or known as ashramas in hindu system.A mans age is believed to be of 100 yrs. so each ashrama is for 25 yrs.
(a) Brahmacharya ashram is the first stage in a human's life. According to hindu system a man should study uptill 25 yrs. these are the years to learn.
(b) Grihastha Ashram is the second stage that is from 25yrs to 50yrs. A man should marry and make family. Bring up his children and apply his studies that he did in brahmacharya ashram to support his family.
(c)Vanaprasth ashram is the third stage in a man's life that is from 50-75 yrs. In this ashram a man along with his wife leaves the home for swadhyayan or self-study. This is the stage where a man starts cutting himself from the rest of the world and starts learning the eternal thruths of life.
(d) Last stage in a man's life is Sanyaas ashram i.e. from 75 yrs to rest of his life. It is the rule of life that one who comes has to go one day. And God is the creator of this life. So a man in this ashrama solely without his/her spouse leaves all the comforts and relations that he made in his entire life and lives a life that made him/her closer to almigthy God.
Division of vedas as told earlier, suits four stages in life.
(i) Mantra Samhitas -they are hymns in praise of the Vedic God for attaining material prosperity here and happiness hereafter. The Mantra portion of the Vedas is useful for the Brahmacharins.
(ii) Brahmanas are explanations of Mantras or rituals. The Brahmana portions guide people to perform sacrificial rites. They are prose explanations of the method of using the Mantras in the Yajna or the sacrifice. The Brahmana portion is suitable for the householders or grihasthas.
(iii) The Aranyakas are the forest books, they contain the phylosophies about life and almigthy that were written and explored in forests. The Aranyakas are intended for the Vanaprasthas or hermits who prepare themselves for taking Sannyasa.
(iv) The Upanishads are the most important portion of the Vedas. The Upanishads contain the essence or the knowledge portion of the Vedas. The Upanishads speak of the identity of the individual soul and the Supreme Soul. They reveal the most subtle and deep spiritual truths. The Upanishads are useful for the Sannyasins. there are 108 upnishads out of which 11 most important.
*Smriti Literature refers to 'memorized' or 'remembered' poetry and epics. It explains universal truths through symbolism and mythology, and contain some of the most beautiful and exciting stories in the history of religion world literature. Some of the most important of Smriti literature are:
1. Bhagwat Geeta- it is the sixth part of Mahabharata, written about the 2nd century BC . It contains some of the most brilliant theological lessons about the nature of God and of life ever written.
2. The Mahabharata - The world's longest epic poem written about 9th century BC, and deals with the power struggle between the Pandava and the Kaurava families, with an intertwining of numerous episodes that make up life.
3. The Ramayana - The most popular of Hindu epics, composed by Valmiki around 4th or 2nd centuries BC with later additions up to about 300 CE. It depicts the story of the royal couple of Ayodha - Ram and Sita and a host of other characters and their exploits
4. Purana- they contains myths, stories, legends, lives of saints, kings and great men, allegories and chronicles of great historical events.They were written to popularise the studies of vedas and to generate the devotion for God. The Puranas were meant, not for the scholars, but for the ordinary people who could not understand high philosophy and who could not study the Vedas.There are 18 puranas. Of these, six are Sattvic Puranas and glorify Vishnu; six are Rajasic and glorify Brahma; six are Tamasic and they glorify Siva.