Shri Veda Vyasa (also known as Badarayana or Krishna Dvaipayana Vyasa) was one of the greatest of all the sages of India. His contribution in compilation of the Vedas is an example of unparalleled erudition. With great perseverance, he searched for all the work of the Rishis. He collected all the mantras and categorized them.
The mantra which is in the metered form and recited for the praise of the deity is called rikor richa. The mantra that can be chanted melodiously is called sama. The mantra in the prose form is called yajus. The mantra meant for daily rites and rituals in prose or poetic form is known as atharva. Thus Veda Vyasa categorized all the mantrasand compiled them in four parts. The four parts thus compiled came to be known as the four Vedas.
The four Vedas are the Rig Veda, the Yajur Veda, the Sama Veda and the Atharva Veda.
The Rig Veda is the oldest of all the Vedas. The Rig Veda is composed of 10552 mantras. It is believed to be the work of 403 sages. The person who knows all the mantras is known asRitwik.
The Yajur Veda is the smallest of all the four Vedas. The knower of this Veda is known asAdhvaryu.
The Sama Veda has 1875 mantras. The knower of this Veda is known as Udgata.
The Atharva Veda has a special place in the field of philosophy and spiritualism. The knower of this Veda is known as Brahma.