Purport

This Shloka along with some other shlokas presents not only an amazing spiritual fact but answer to one of the most complex subjects of science that is that the reation and state of universe.(We would discus those subjects separately)
Bhagvan Shri krishna describes, that all Lokas starting from Bramha loka and downwards are subject to creation and destruction. Hence all living beings which reside on some of those planets also go through the cycle of birth and death.

But then Bhagvan Shri Krsihna also describes how his loka, which is also called as Goloka or Vaikuntha is free from such recurrence creation and destruction.

Those human who able to reach to the realm of Bhagvan Krishna hence becomes imortal and reside without facing any death for eternity.

Note: Some very complex subjects, like relativity of time, time and eternity, relative span of life etc which relates with this Shloka would be discussed shortly.