Brahma, in Hinduism, is the Creator in the Trimurti, the largely artificial trinity with the other two partners, Vishnu, the Preserver, and Shiva, the Destroyer.
The worship of Brahma in the Trimurti is the oldest; he appears in the Vedas as Prajapati, Pitamaha, and Hiranya-garbha; he is seen in the Brahmanas, but afterward his importance wanes before the emergence of the non-Aryan Shiva and Vishnu.
However, the role of Brahma is well defined in Hindu cosmology. The world creates and dissolves in a long process, called the days and nights of Brahma.
Each day and each night lasts one thousand years of the gods, and each year of the gods corresponds to twelve thousand years of men. Every day of Brahma, which sees the emanation of the universe from divine substance and its dissolution again, lasts twelve million years.
During the night of Brahma, all remains are absorbed in one Brahman (note the difference), waiting for its recreation. Each year of the gods is in turn divided into four yugas. In the night of Brahma, God remains in dreamless sleep, inactive, all being fathomless rest and boundless peace. During the night Vishnu lies unconscious on the Cosmic Serpent Shesha.
At the coming of dawn a lotus blooms from Vishnu’s naval, out od which springs Brahma the Creator, while Shiva, the agent of reabsorption (samhara), springs from his head, to send the universe through for yugas.
The Buddha (in Digha Nikaya) denied and denigrated the doctrine of Brahma the Creator. Brahma’s cult today is infrequently observed among Hindus. A.G.H.
Source: 83, 70.