Nirguna

Para Brahman (Sanskrit:परब्रह्मन्) (IAST: Para Brahman) is the "Highest Brahman" that which is beyond all descriptions and conceptualisations. In Advaita Vedanta Nirguna Brahman (Brahman without qualities) is Para Brahman. In Vaishnavism and Shaivism Vishnu and Shiva, respectively, are Para Brahman.

Para is a Sanskrit word that means "higher" in some contexts, and "highest or supreme" in others.

Brahman connotes the Highest Universal Principle in Hinduism, the Ultimate Reality in the universe. In major schools of Hindu philosophy it is the material, efficient, formal and final cause of all that exists. Brahman is a key concept found in Vedas, and extensively discussed in the early Upanishads.

Para Brahman means the "Highest Brahman". It is found in early Advaita Vedanta literature.

Nirguna Brahman (Devanagari निर्गुण ब्रह्मन्, Nirguṇa Brahman), Brahman without form or qualities, is Para Brahman, the highest Brahman. According to Adi Shankara, Nirguna Brahman is Para Brahman, and is a state of complete knowledge of self as being identical with the transcendental Brahman, a state of mental-spiritual enlightenment (Jnana yoga). It contrasts with Saguna Brahman which is a state of loving awareness (Bhakti yoga). Advaita Vedanta non-dualistically holds that Brahman is divine, the Divine is Brahman, and this is identical to that which is Atman (one's soul, innermost self) and nirguna (attribute-less), infinite, love, truth, knowledge, "being-consciousness-bliss".

According to Eliot Deutsch, Nirguna Brahman is a "state of being" in which all dualistic distinctions between one's own soul and Brahman are obliterated and are overcome. In contrast, Saguna Brahman is where the distinctions are harmonized after duality between one's own soul and Brahman has been accepted.

...
Wikipedia