An epilogue is a concluding section of a literary work that stands outside the main body of the text. It is the opposite of a prologue, which begins a work. Epilogues often inform readers of events that occur after the end of the plot. Epilogues can offer reflective commentary or—in plays—address the audience directly. The moral or lesson briefly summarized at the end of a fable is also sometimes referred to as an epilogue. 

Epilogue evolved from the Greek word epilogos, from epi (“upon”) and logos (“word”). 

Shakespeare used an epilogue at the end of his A Midsummer Night’s Dream (act 5, scene 1 : lines 440–455):

If we shadows have offended,
Think but this and all is mended:
That you have but slumbered here
While these visions did appear.
And this weak and idle theme,
No more yielding but a dream,
Gentles, do not reprehend.
If you pardon, we will mend.
And, as I am an honest Puck,
If we have unearned luck
Now to ’scape the serpent’s tongue,
We will make amends ere long.
Else the Puck a liar call.
So good night unto you all.
Give me your hands, if we be friends,
And Robin shall restore amends.

Renaissance playwright Ben Jonson often used epilogues, in some cases to praise his plays and defend their merits to potential critics. In his play Volpone, the titular character steps forward after the cast has exited and cleverly encourages the audience in their applause:

“The seasoning of a play, is the applause.

Now, though the Fox be punish'd by the laws,

He yet doth hope, there is no suffering due,

For any fact which he hath done 'gainst you;

If there be, censure him; here he doubtful stands:

If not, fare jovially, and clap your hands.”

In novels, the epilogue can serve to tidy up any loose ends that weren’t resolved in the primary plot or to show events that take place long after those of the primary plot. At the end of the Harry Potter series, for example, the epilogue contains a time jump to where Ron, Harry, Ginny, and Hermione all take their kids to the train station to take them to Hogwarts.

see: prologue, fable