Essence of Mundakopanishad - Paravidya and Aparavidya

Mundakam 1 - Section 1  ( Om Peace ! Peace !! Peace !!! )

Brahma, the creator and protector of this universe, arose as the first among Gods. He expounded the science of the knowledge of BRAHMAM (Brahma-Vidya), the foundation of all knowledge (all sciences) to Atharvan, his eldest son. Whatever Brahma told Atharvan, that knowledge Atharvan gave to Angir. Angir taught it to Satyavaha of the family of Bharadvaja, and Satyavaha taught to Angiras the knowledge traditionally obtained by the success on of teachers.Saunaka, the great householder, approached Angiras in the manner laid down by the scriptures and questioned; What is that, O Bhagavan, which being known, all this becomes known?

BRAHMAM ( The Universal Cosmic Energy ) is the cause of this world. By attaining the knowledge of BRAHMAM, the effect, the world, is comprehended.

Angiras replied to Saunaka: There are two kinds of knowledge to be acquired. So those who know BRAHMAM say, Para and Apara, i.e., the higher and the lower.

Para is the knowledge of BRAHMAM.

Apara is that which treats of the means and fruits of good and bad actions. The object of the lower science is to show the cause of virtue and vice and their consequences. Apara Vidya is ignorance. It teaches nothing ultimately real. It must therefore be rejected in the end.
The lower knowledge is the Rig-veda, the Samaveda, Yajurveda, Atharvaveda, Siksha (phonetics), Kalpa (code of rituals), Vyakarana (grammar), Nirukta (etymology), Chhandas (metre) and Jyotisha (astrology). But the higher knowledge is that by which the immortal is known.

BRAHMAM can be obtained only by the removal of ignorance.
Brahma-Vidya is called Para-Vidya, because it is a help to salvation, it leads to the attainment of the BRAHMAM.

Para-Vidya is the knowledge of the immortal which can be known through the Upanishads.That which cannot be seen or seized, which has no origin, which has no properties, which has neither ear nor eye, which has neither hands nor feet, which is eternal, diversely manifested, all-pervading, extremely subtle and imperishable, the wise regard as the source of all beings.

BRAHMAM sees without eyes and hears without ears. Decay is not possible in BRAHMAM, as it is ever full and self-contained. That knowledge by which the immortal BRAHMAM is known is what is called PARAVIDYA