("illumination") is a Sanskrit word that means
"illumination." Prakasha is one of the bipolar oppo sites that are
used to define the essence of all reality in Hindu tantra, a hidden,
ritual-based religious activity, with its opposite half being reflection
(vimarsha).
These two concepts are especially significant for the
formation of the world, which is believed to occur when the ultimate Brahman's
pure and radiant awareness (prakasha) becomes self-conscious via the reflection
(vimarsha) of this original consciousness.
The absolute transforms from a single awareness into a dual
divinity—the deity Shiva and his consort Shakti—whose ongoing interaction
creates the universe.
Jaideva Singh, Pratyabhijnanahrdayam, 1982, is a good source
of knowledge.
Also see cosmology.