Drabbles are a bit of a hot topic, and I've run across a few debates started by people who don't like them. Now, this is nothing unusual in fandom, there seems to be at least one person who doesn't like any given thing, and I usually just shrug my shoulders and move on. The problem with the drabble debates, however, lies in how people are defining drabbles.
There are those who are using the term drabble to mean any story under 500 words. There is at least one person I have seen use the term to mean any story under 1000 words, and she said she picked up that definition from an actual fic community. Appalling thought, that, since it means yet more people are going to be wandering around with this misconception of what a drabble is. Generally speaking, I try to be an "anything goes in fandom" kinda gal, and just take people's individual definitions in stride. The thing is, let's say you've got someone who declares she doesn't like drabbles, and you get someone who agrees with her, and someone who doesn't, and these two someones start debating with each other, and one or the other of them mentions the 100-word limit, and the original poster pops up and says, "Oh, I define drabble as anything under 500 words." Now both the person who disagreed with her, and the person who agreed with her, are left blinking at her clarification. The debate is completely derailed, and the person who agreed with her often comes back to say, "Oh, well, I actually like quite a few stories in that word limit. I just don't like stories that are exactly 100 words, which is how I define drabble." Instead of a debate on the relative merits of drabbles, you suddenly have a debate on what a drabble is. Except you really don't, because those who were interested in discussing fic of 100 words really aren't interested in discussing whether the term "drabble" actually means fic of 100 words.
Conversely, you can have an original poster who says she doesn't like drabbles, and someone pops up to agree with her, saying, "I just don't like stories under 1000 words. Give me something meatier." The OP replies, "Oh, my favorite story length is 500-1000 words. I just don't like drabbles, I think they're too short to be worth my while." The person who agreed with her says, "But anything under 1000 words is a drabble, so I'm not sure what you're saying you dislike," and again the debate devolves into defining "drabble."
Definitions drift with usage and words take on new meanings, but usually it's because there's not already a perfectly serviceable word that means what the user wants. Well, in the case of stories 500 words and under, there is. In the case of stories 1000 words and under, there is. In the case of stories 17500 words and under, there is, and I'm going to give you those terms now.
A drabble is a story of exactly 100 words. It's debatable as to whether or not the title is included (the common definition I've seen allows for one to fifteen extra words for the title), but the limit itself is not debatable. A drabble and a half is exactly 150 words. A double drabble is 200 words, and anything over that really stops being a drabble, but in fandom, any story in increments of 50 words is often still referred to as some permutation of drabble, ie double drabble and a half, triple drabble, triple drabble and a half, quad-drabble, etc. Even in fandom, however, the key is that your word count is exactly on that 50 word increment mark. Otherwise, you are not writing a drabble of any kind.
So what are you writing? Well, in the pro lit world, any story under 500 words is flash fiction. It's a term that used to be widely-used in fandom as well, but I think the influx of fans who didn't first pass through sf lit fandom or come from some other area of the pro lit world has negatively impacted both knowledge and use of the term. So, if you didn't know the term before, here it is. When discussing fic under 500 words that is not exactly 100 words, the term you want is flash fiction. Or even flashfic, or minute fic, or sudden fic, postcard fic, fast fic, quick fic, and a few others. Flashfic is the most common and well-known, but there are a few alternatives. The point is, none of those alternatives are drabble.
Fic that is over 500 words, but under 1000, is generally known as a short short. Some magazines and anthologies actually use short short and flash fiction interchangeably, because of space constraints, but in online fandom, we generally don't have to worry about such things. So, short short.
1000 and over, up to 17500, is a short story. It doesn't matter if it's not as long as you personally prefer, it is still a full-fledged, honest-to-god, bona fide short story. And that's another thing. It seems like a lot of people are just defining drabble as any story that is not as long as their personal preference. No. Just no. Drabble is not a negative term, and your personal preference does not a sound basis for literary terminology make. It's like suddenly deciding to use adverb to mean any word you don't like. Not only are you going to confuse people with your usage, but you're also not doing your stance any favors by coming across as ignorant as to the actual meaning of the word.
So, just to review, 100 words=drabble. 500 words and under=flash fiction. 500-1000 words=short short. 1000-15000 words=short story. At 17500, you've ventured into novella/novelette territory (I've seen it split so that 17500 to 25000 is a novella, and 25000 to 40000 is a novelette. I have also seen it split the other direction. Generally, the two terms are used interchangeably). At 40000, congratulations, you have yourself a novel.
But wait! I hear you cry. What about vignettes? What about chapters? I'm so glad you asked, because now I can answer. A vignette has nothing to do with word count. Customarily, it is under 1000 words, but the significant thing about a vignette is the theme, not the word count. A vignette is meant to give new insight into a character or the relationship between two or more characters. Most vignettes don't involve a lot of action. Some of them also don't involve a lot of dialogue. The important thing is the illumination of character or relationship. That's what a vignette is all about.
As for chapters, they have no impact on how your story is classified by word count. Let me repeat that. Chapters have no impact on how your story is classified by word count. If you write a chaptered story that is under 17500 words, you have written a chaptered short story. You can call it a novel if it makes you feel better, but the word count will not agree with you. Those who classify stories by word count will also not agree with you, and they do indeed have the weight of historical usage and the pro publishing industry behind them. You don't have to care about that, of course, but it's good to be aware of it, so if someone calls your chaptered fic a "short story" in their review, you know it's not an insult. It's a quantitative term, not qualitative.
Just like drabble, come to that.
Oh, and one other thing all of the above are: Real fiction. They're words strung together, telling a fictional story. They may not be fiction you personally like, or consider successful, but they are most assuredly real. Kindly do not confuse the two, as it only muddies the waters of communication further.
While I'm on that subject, I'll make a brief mention of the term "ficlet." It's fandom-specific, from what I've been able to determine, and used interchangeably with both flash fiction and short short, depending on who's using it. It's a term I particularly dislike, since I feel it perpetuates the misconception of fiction under a certain word count as not being "real stories," but it does seem to be in very widespread usage.
There you go, a crash course in literary terms as they apply to story length. You may think me pretentious for laying them out, or wanky, or elitist, or what have you. That's fine. Just keep in mind, another thing I am is right. This post is not a statement of opinion, it is a list of facts. You may not like them, but that makes them no less valid. Here, have some proof: Writer's Market's literary definitions, including short story, novelette, and novella. Novella as defined by the Hugo and Nebula awards committees. Word Smitten's definition of flash fiction. Writing World essay on flash fiction and its various alternate names (note that drabble is not one). A thread post to the question of what flash fiction is, citing various definition links. Compare all of these with these professional definitions of the term drabble.
It's all about clarity of communication, folks. Otherwise, we're all just talking gibberish at each other. Which can be fun, but really doesn't help you get your point across.