Hi Narcis!

This is a great question. I definitely tend to use terms interchangeably so I am using this as an opportunity to investigate these terms for myself too. :) These definitions are my understanding of the terms although others may use them differently.

Flashfic/ficlet: Flashfic comes from "flash fiction" which is a short story of a few hundred words although typically under 1k. Even though it is short in length, it is usually a completed narrative. It looks like ficlet is also used in this capacity from what I can see online (and also from personal experience).

Snippet: Any excerpt from a completed or ongoing work, whether an entire page, just a few paragraphs, or even just a line of dialogue.

Drabble: According to a brief internet search, a drabble is a work of exactly 100 words. I definitely did not actually know that haaha and instead have used it to refer to any brainworms/more open-ended musings or thoughts on a particular concept or idea. This is very good to know.

If you're looking to post stories in thread form on twt, you could consider labeling them simply as 'thread fics,' although like you mentioned, you can also abstain from labels entirely and let people engage with your work as is :) I guess the difference in how I view the terms with relation to my own work is usually the "completeness" of the idea. That is, whether I'm discussing the concept of a story and how I might write it vs. actually writing it out or sharing a snippet from an ongoing draft, etc.

I'm definitely not the authority on fanfic terminology, but I hope that is helpful! Maybe others can chime in too if they see this. Thanks for your question and happy writing! <3