What are the purposes of a prologue in a play

Explanation:

Prologue comes from the Greek term prologos, which means “before word,” is an opening of a story that establishes the setting, and gives background details. Generally speaking, the main function of a prologue tells some earlier story, and connects it to the main story.

imparadis't in one anothers arms  

the happier eden, shall enjoy their fill  

of bliss on bliss, while i to hell am thrust,  

where neither joy nor love, but fierce desire,  

among our other torments not the least,  

still unfulfill'd with pain of longing pines;  

yet let me not forget what i have gain'd  

from their own mouths; all is not theirs it seems:  

one fatal tree there stands of knowledge call'd,  

forbidden them to taste: knowledge forbidd'n?  

suspicious, reasonless. why should their lord  

envie them that? can it be sin to know,