Published

published is wonderful option to create draft or a post with rough cuts.

published is basically having three option

• true - True, this is optional, but its basically the same as not supplying the published state at all. It will compile your post and make it publicly available.
• private - Private is a post that will not be compiled at all, this will stay as markdown, good for when you want to begin writing something but not have it show up online yet.
• draft - Draft is basically a finished or rough cut blog post that you will publish soon, it will be compiled to /drafts URL and be publicly accessible (either via a known page or the direct URL)

Example

---
title: Snow gets Drafts! 
layout: post
categories: Snow 
published: draft
---

Files will go to draft folder.

For further reference check out Phillip's blog