[quote=@Prince of Seraphs]
If we're getting clinical I believe fables have a more structured and poetical writing style but past that their is very little difference between them and fairy tales. If you want me to choose I'll say write a fairy tale but I don't believe there is much difference.

Also I believe the earliest written fables date back to Greece in 550 BC but as a style of story telling that was propagated by oral tradition it is more than likely that they are older than that.
[/quote]

Yes, but the modern Fable was popularized by Germans at the start of the 19th century during the romantic-period, as were the so called "Volksmärchen", literally "people's fairy tales", like Rapunzel and the Golden Goose and Red Riding Hood, called "Rotkäppchen" here. 
Mostly because of the desire for an identity as a nation, as Germany was divided up into hundreds of smaller states where the people felt they all should belong together in one whole country.

Fables are different from fairy tales in a whole matter of ways. 
This describes it pretty accurately for a website in English. German websites are a lot more in-depth.

http://www.differencebetween.com/difference-between-fable-and-vs-fairy-tale/

As you can see the whole "moral" thing is not a fairy tale thing, but belongs to the fable. Fairy tales are more or less "epic adventures with magic and stuff". Fairy tales mostly have the conflict of good vs evil, whereas fables try to teach morals like "do not steal" or "do not lie" etc.
Yeeeah and fables have talking animals and plants which always have the same character, the lion as the king, the raven as the misleading character and the magpie as the thief.

I think what you want for this contest is a combination of both, right? The "epic" story of a fairy tale, without magic and magical creatures, but with a moral to the story?





P.S.: Sorry for going on a nerd rant here, but as a German citizen, I feel it is my duty to protect my cultural identity. That's basically all my country has left.