Perspectives on Brahman
For the Christian or Westerner I would simply describe Brahman as a view of the world in which the Holy Spirit is the creator God, rather than God, Elohim, or Jehovah.
In Eastern thought the creation is not just the material world as we see it, but our senses, emotions and thoughts, as well. He is not merely the objects of our senses (which in the Eastern view include our thoughts and emotions), but the senses themselves within the the physical body where they reside and disjoint from it as well.
You could describe Brahman as a/the singular entity or God that is not so much the Supreme Being (which He/It is) but a/the being of the Supreme Essence of Being, the origin of being, the Supreme Essence of Being as a/the singular, unique, self-aware, conscious, consciousness/life-giving entity or being in its own right, in both a static and a dynamic sense - the Eternal Om.
The being that being derives from.
The word being I use here as both a noun and a verb.
The being that is the origin of space, light and time.
He is the A that can't be called the A because there is no B to the left, right, above nor below, north, south, east, nor west, for Him to be compared to.
He is the Alpha without an Omega.
To make things more interesting He is non being as well.
Here are some links to Brahman.
A Catechism of Enlightenment - A Commentary on Shankara’s Upadeshasahasri