As in things you write on paper and fold up and stick in envelopes and lick a stamp (except they're just stickers so you don't actually do that) and drop in the mailbox letters.
In stories today, letters function as either a mysterious, ancient plot device arriving from one's great-great-great Uncle (guilty of this one), a romantic plot device (also guilty), or physical evidence when explaining how a certain character doesn't understand the e in e-mail (not guilty....yet).
BUT GUYS. Despite holding down the cliche fort, letters are incredibly fun to write. Because you can't backspace on a letter. Which allows for possibly the only time (aside from journal entries) to use the
Deleted thoughts are amazing. Incredible. Kind of like the blooper reel of life. My favorite part of reading handwritten drafts of my stories or essays are the crossed-out words, phrases, and paragraphs (One story had an entire page crossed out and rewritten in the margins.) But this really only happens on paper, and the best deleted scenes occur in letters, because letters have a more significant purpose than even essays or (some) story drafts or grocery lists. Letters are a specific message in a revelatory style, and the strikethroughs of fumbling for words can be
(See what I did there?)
(Yeah...of course you did. Now go do your own!)