Once you are done working on draft changes to an article it is time to publish it for the public to see.
Click on an article title to view the article
Select the version to publish
From the Revisions menu, select the version you would like to make visible to the public. It will most likely to the latest version, which is selected by default.
Note that the (current) version isn't the selected version. That's because the draft version is selected, but it is not the "current" version that is published.
Click Publish this version
The selected version becomes the current version and it is now visible to the public.