As you might have guessed from the title, flash fiction is short fiction. On our site, our longest-running theme is the 100-word story (that doesn't include the title, by the way), but there are also sections for longer and shorter stories.
The Guardian published an excellent article on writing short stories by the author David Gaffney, which you can read here.
In the meantime, here is a recent example of flash fiction from the website:
ALL IN THE NAME OF CONVENIENCE, BY ALISON McHARG
Lift from bag to cupboard. Separate apples from pears. Assess what needs frozen, what stays in the fridge.
Where’s the bleach – surely not packed with bread?
“Did you get Mini Mars Bars?” a disembodied voice, calling from the pantry.
“That’s them next to the flour.”
“I can’t see any flowers, there is sugar, though, We didn’t need that this week.”
There isn’t time for a monologue on the vagaries of the English language…
Shopping done from a tablet. It all feels like hard work – I need a coffee – problem is, I got coffee ice cream instead. Sigh.