BRAHMAN, BRAHMA, VISHNU, SHIVA

BRAHMAN is the impersonal, all-pervading essence of the Universe. Having no mass, it can be measured by volume.

BRAHMA is a divine personification of BRAHMAN as the instant of initiation of the next BRAHMA'S DAY.
VISHNU is a divine personification of the time-span of one BRAHMA'S DAY.
SHIVA is a divine personification of the time-span of one BRAHMA'S NIGHT.

VISHNU and SHIVA are two equal time-spans which taken together, represent one iteration of the Universe. This cycle repeats eternally i.e. without beginning or end.
BRAHMAN itself is not affected in any way, qualitatively or quantitatively, by the progress of this cycle. As all of space and all of the matter in the Universe is within the volume of BRAHMAN and as BRAHMAN is eternal and continuous i.e. not subject to any greater cycle, BRAHMAN is the supreme being. Some Brahmin (varna) consider BRAHMAN itself to be self-aware and to give assent at the start of each incarnation of VISHNU, the BRAHMA point, after which SHIVA must follow.
One cycle is then
BRAHMA 0 time
VISHNU 9 billion years
SHIVA 9 billion years.

During VISHNU, the law of KARMA operates and the Universe becomes more and more energetic, having most kinetic energy, and all matter in one piece, at the very end. This is consolidation.
During SHIVA, there is only one cause and effect progression, that of the single mass being converted, by the application of its kinetic energy, to a large number of the smallest possible particles. This is disintegration.
At the end of SHIVA, all matter in the Universe has been converted to a single spinning disk-like mass of protium (Hydrogen) atoms, stationary and at the centre of BRAHMAN'S volume.

In India, there are many temples to VISHNU and also to SHIVA, I have been told that there is only one BRAHMA temple.