Draft articles will immediately been seen in the archives area on the front of your site. They will automatically flow into the front of the site if you are using a category list or any other automatically populated elements. You can then copy and paste these articles into any desired elements around the site for a prominent view.
Draft articles will remain only searchable in the administration area until the Draft is published. Even if you try to paste the draft article into an element the article will not show up.
The reason to use the draft system is for work flow reasons. You can start writing an article in the admin area and if you are waiting on further information or multimedia you can just save it as a draft. When you obtain the information needed you can add it and publish the article.
Lastly you can grant your editors permission to upload content to the site but not give them access to publish. Everything that editor saves will be in draft mode and the online editor or editor in chief can publish those stories as needed.