are marginal energy of Krishna

 
Sometimes he merges into the dark material nature and identifies himself with matter, and sometimes he identifies himself with the superior spiritual nature. Therefore he is called the Supreme Lord's marginal energy.
In Vedic literature the living entity is called jivatma and Brahman, but he is never called Parabrahman. The living entity (jivatma) takes different positions-sometimes he merges into the dark material nature and identifies himself with matter, and sometimes he identifies himself with the superior spiritual nature. Therefore he is called the Supreme Lord's marginal energy. According to his identification with material or spiritual nature, he receives a material or spiritual body. In material nature he may take a body from any of the 8,400,000 species of life, but in spiritual nature he has only one body. In material nature he is sometimes manifested as a man, demigod, an animal, a beast, bird, etc., according to his karma. To attain material heavenly planets and enjoy their facilities, he sometimes performs sacrifices (yajna), but when his merit is exhausted, he returns to earth again in the form of a man.    (More...)

Link to this page: https://prabhupadabooks.com/?qg=6828