the.com/flash fiction

means A complete story told in a very small number of words—often under a thousand, sometimes under a hundred—that still manages to have a beginning, middle, and end.

from The term rose in American creative-writing circles in the late 20th century, borrowed from the camera flash: a burst of light that illuminates everything at once and is gone. The name stuck because it captured the form's whole trick—compression and instancy rather than length. Related labels like 'sudden fiction' and 'microfiction' emerged around the same time from the same impulse, with editors and anthologies of the 1980s-90s helping fix 'flash fiction' as the popular term.