Moksha
its a Hindu smbol that means absolute knowledge & all creation. It represents perfection. It represents an all powerful, all knowledgeable, supreme being. It also means divine energy. Its kind of line Neo in Matrix Revolutions, after he starts seeing everything in Orange glow. He starts reaching that state, that no Human is supposed to reach and it leads to his end or rather his freedom and liberation from a physical form ... to his Nirvana.
brahman
In a Supreme Creator.
The amighty god,Brahma.
Prayan is a Hindu name and can mean "Supreme Intelligent"
He is the Hindu god of perseverance.That is right, and for most hindus, the Supreme God.
Hindus believe in One Supreme god (Brahman) and many manifestations of the one supreme god.
There's none as "supreme god". God itself is considered as "supreme". The shape and form we give to offer prayers is upto each individual.
The Lord Shiva is a mythical deity of the Hindu. He is considered as a supreme soul or a supreme god that is called as The Destroyer or The Transformer.
The Hindu would just say that all the Hindu gods are the subordinates of the supreme Hindu god Brahman and therefore, irrespective of which of the infinite Hindu god he is worshiping, he would always be worshiping some part of Brahman.
Reincarnation
Murti is considered as Supreme God himself. By washing it Hindu believ that they are giving shower to God. Which is very good for karma.