Publishing is the final step of security. 

 

Unpublished content is invisible to users with only view, print, or download rights. After the content is published, these users can access it. If your project hasn't launched yet, only Project Admins and Reviewers with Manage Permissions can access and edit all unpublished content.

 

By default, Reviewers in roles with Manage Permissions can't publish or unpublish content. 

To enable publishing and unpublishing for a new Manage type role:

1. Go to the Permissions tab and click Add Role.
2. Select Manage and click Next.
3. Name your role and click Next.
4. Select Download Options for the Manage role and click Next.
5. Select High Level Permissions and click Next.
6. In the Feature Access page tick the checkbox for Publish/Unpublish Files and click Next.
7. Confirm in the Summary that Advanced Features: Publish/Unpublish Files is listed and click Finish and Create Role.
   
   

To enable publishing and unpublishing for an existing role:

1. Go to the Permissions tab.
2. Select a role by ticking the checkbox next to it's name.
3. Click Feature Access. 
4. Tick the checkbox to enable Publish / Unpublish documents.
5. Click Save.

For more information see the article: 
How do I check the published status of my files?/ How can I filter for unpublished files?