It is important to distinguish between a prologue and an epilogue when you are structuring a narrative. Generally speaking, a prologue comes before the main story and an epilogue comes after it.
A prologue is usually used to provide the reader with some important information about the setting or characters before the main action begins. For example, the prologue of a story could include a brief explanation of the world's history or an introduction of the protagonists and antagonists.
An epilogue, on the other hand, usually provides resolution and closure to the story after the main action has been concluded. It can explain what happened to the characters after the end of the plot and show the results of their journey.
In summary, a prologue typically comes before the main body of a story, and an epilogue comes after it. This order is important since it allows the writer to provide crucial and relevant information to the readers while also bringing closure to the story.