Save changes as a draft if you don't want the changes to appear to the public. Only other authors working on the article will be able to see the changes.
Save as draft
If you don't want the changes you made to an article to appear to the general public then click the Save as Draft button when you want to save the changes. The changes will be saved to a draft on the server and will not be visible to the public.
When you are ready to make the draft version available to the public you can publish it.