A drabble… I’m not exactly sure where it comes from, is a format for fiction which is exactly 100 words (not including the title). It can’t be any more or less than one hundred.
Exercises like a drabble, writing to exactly a hundred words, are good to play with. I liken this to writing a comic script to make what is effectively an act break at the end of each issue. To making a dramatic beat preferrable at each turn of the page.