Explanation:

On Rig-Veda Rig-Veda is oldest literature of the world and is known as “First testament” of mankind. The famous Gayatri Mantra comes from third Mandala of Rig-Veda. The first hymn (1.1) of Rig-Veda is dedicated to Vedic God Agni. One entire Mandala (ninth) is dedicated to the Vedic beverage Soma.  On Yajurveda It contains rituals for yajnas and is ascribed to Advaryus who prepared ground for Yajnas. It is world’s oldest prose literature.  On Sam Veda Samaveda contains the rhythmic compilation of Hymns for Rig-Veda. The 1549 hymns are there to be sung at the Soma Sacrifice by a special class of Brahamins called Udgatris. Gandharveveda is Upaveda of Samveda. Panchavisha, Shadvisha and Jaiminiya Brahmanas are attached to Samaveda. On Atharvaveda Atharvaveda is chronologically the latest Veda. It describes the popular beliefs and superstitions of the humble folk.