śhrī bhagavān :- uvācha akṣharaṁ brahma paramaṁ svabhāvo ’dhyātmam uchyate bhūta-bhāvodbhava-karo visargaḥ karma-sanjñitaḥThe Supreme Indestructible Entity is called Brahman; one’s own self is called adhyātma. Actions pertaining to the material personality of living beings, and its development are called karma, or fruitive activities.
Shree Krishna says that the Supreme Entity is called Brahman (in the Vedas, God is referred to by many Names and Brahman is one of them). It is beyond space, time, and the chain of cause and effect. These are the characteristics of the material realm, while Brahman is transcendental to the material plane. It is unaffected by the changes in the universe, and is imperishable. Hence, It is described as akṣharam. In the Bṛihadāraṇyak Upaniṣhad 3.8.8, Brahman has been described in the same manner: “Learned people speak of Brahman as akṣhar (indestructible). It is also designated as Param (Supreme) because It possesses qualities beyond those possessed by Maya and the souls.”
The path of spirituality is called adhyātma, and science of the soul is also called adhyātma. But here the word has been used for one’s own self, which includes the soul, body, mind, and intellect.
Karma is actions performed by the self, which forge the individual’s unique conditions of existence from birth to birth. These karmas keep the soul rotating in samsara (the cycle of material existence).