Answer:
They provide background information to help the reader understand events.
Explanation:
Flashbacks talk about a previous event, meaning they can explain the current situation in some way, shape, or form, be it how a friend was made or why so-and-so hates bars.
However, internal conflicts could be a good second answer as it could answer the question of why this is such a big deal (I.E. why being forced to throw out a rose when it was touched by a crush during a herbology lesson or something is something the protagonist doesn't want to do despite the fact it's been dead for weeks, though, again gives context for why said rose is important).
From what I remember and what I've read there was a lot of "madness" "morbid" and seemingly made up diagnosis by husbands of their wive's "hysteria". A lot of stories portrayed people as being "manic," "delirious," "withdrawn," "depressed" (melancholy). I hope this helps.
