As explained elsewhere in this guide, campaigns are deployed to the target server specified in the ATG Outreach project workflow. ATG Outreach includes two workflows, a single-target workflow that is typically used to deploy campaigns to a production server, and a dual-target workflow that can be used to deploy to both a staging server and a production server. The use of a staging server allows you to test campaigns before you deploy them to your live site. You deploy first to the staging server, where you verify that the campaign works as designed. Then you deploy to the live production server, at which point the campaigns are visible to customers.