The vedic literature of the Aryans is divided into two broad categories:
early Vedic literature and the later Vedic literature. The Rig Veda, the first of the Vedas, is probably the earliest literary work that humanity possesses. It contains hymns in praise of diff. gods and goddesses like Indra, Agni and Varuna. It consists of 1028 hymns divided into 10 "Mandalas" or books.
The later Vedic age includes Yajur Veda, Atharva Veda and Sama Veda. Each of these Vedas have 2 parts:-
1. the Samhita 2. tha Brahmana
The Samhita contains the hymns to be sung at rituals whereas the Brahmana contains the meanings of these hymns. Besides there are the holy Upanishads also.