Parmatma is the original source , the Illuminating live almighty . For an instance a live source of unlimited energy amounting to many times of that of a sun .
So as defined by gita is…
Divi sooryasahasrasya bhavedyugapadutthitaa;
Yadi bhaah sadrishee saa syaadbhaasastasya mahaatmanah.
If the splendour of a thousand suns were to blaze out at once (simultaneously) in the sky,
that would be the splendour of that mighty Being (great soul).
Pashyaami twaam deeptahutaashavaktram
Swatejasaa vishwamidam tapantam.
. I see Thee without beginning, middle or end, infinite in power, of endless arms, the sun
and the moon being Thy eyes, the burning fire Thy mouth, heating the entire universe with Thy radiance .