Drafts

WordPress gives you the option to save a draft of your post, so that you don't have to publish it right away, but can still save your work. If you've started writing a post and want to save a draft, just click on the Save Draft button at the right (in the Publish box), instead of the Publish button. Even if you don't click on the Save Draft button, WordPress will attempt to save a draft of your post for you, about once a minute. You'll see this in the area just below the content box. The text will say Saving Draft... and then show the time of the last draft saved:

At this point, after a manual save or an autosave, you can leave the Edit Post page and do other things. You'll be able to access all of your draft posts from the Dashboard, or from the Edit Posts page.

In essence, drafts are meant to hold your work in progress, which means all articles that haven't been finished yet, or haven't even been started yet, and obviously everything in between.