Brahman is the basis, source and support of everything in the universe. Its nature is Absolute Being (sat), Consciousness (chit), and Bliss (ananda). Brahman is eternal, infinite, formless, all-embracing, and everything that ever was, is now, or ever will be. Brahman is the Ultimate Reality.
Using mere words to define a concept as vast and complex as Brahman is bound to fail; therefore, Hinduism has developd a reductive device to help us approach and feel connection to that which cannot be comprehended in its entirety.
First, the principle of Brahman is divided into two realities; Brahman itself – unchanging, absolute Truth and absolute Reality; and Maya, the illusion of our perceived reality, an illusion which lives, dies and is reborn on the wheel of time.
Brahman is also divided into characteristics that are deemed male (Purusha) and female (Prakriti), attributes embodying as individual gods and goddesses, each with their own set of responsibilities and temperament as well as a unique human-like physical form. For example, when Shiva embodies the Purusha principle, it is Uma who embodies the Prakriti.
“Ye yatha mam prapadyante tanstathaiva bhajamyaham.”
“I come to you in whatever form you worship Me.”
Bhagavad Gita 4:11
Generally speaking, the deities are not divine in their own right but specific physical manifestations of Brahman (note 1). A metaphor might be that if Brahman was a vast cosmic diamond, the individual gods and goddesses are facets rather than individual diamonds.
Note 1 – Followers of sects such as Saivites or Vaisnavites or Shaktics, however, may argue their chosen god or goddess is Supreme over all other concepts or manifestations of Brahman.