Writer (can write and submit for approval to an editor)
To write an article as a writer within a publication you create an article as usual. On the left-hand side of the screen, you have a "Location" drop-down where you can select either your own handle or the handle of a publisher. You can then optionally select a category from the "Category" dropdown.
When you save (with a publication selected), the article is submitted to the editor and the article is no longer available for you to edit.
Writing for publication
Steps to take:
Select Create article
Write your article
Save as draft as you wish
When you are ready to submit it to the editor of the publication