Private Content
Private content is published only for your eyes, or the eyes of only those with authorization permission levels to see private content. Normal users and visitors will not be aware of private content. It will not appear in the article lists. If a visitor were to guess the URL for your private post, they would still not be able to see your content. You will only see the private content when you are logged into your WordPress blog.
Once you change the visibility to private, the post or page status changes to “Privately Published” as shown. Private posts are automatically published but not visible to anyone but those with the appropriate permission levels (Editor or Administrator).
WARNING:
If your site has multiple editors or administrators, they will be able to see your protected and private posts in the Edit screen. They do not need the password to be able to see your protected posts. They can see the private posts in the Edit posts/Pages list, and are able to modify them, or even make them public. Consider these consequences before making such posts in such a multiple-user environment.