The word brahman is a Sanskrit word. It is derived from the Sanskrit root brh, which means “to grow or expand.” So Brahman is that which grows and causes other things to grow.
In ancient vedic science and philosophy, the word brahman is used for both parmatman and atman. Para brahman is referred to as the Paramatman, meaning supreme soul or supreme self and brahman is referred to as the atman, meaning soul or self.

Brahman is the ultimate principle of everything.

Brahman is the ultimate reality