The library at /admin/campaigns/templates shows the built-in templates and yours. Built-in templates can be used as they are; templates you created show an Edit link. Other employers' templates are never shown to you, and yours are never shown to them.
Merge fields are written in double braces and filled for each recipient when the message is sent — a first name or a job title, for example — so one template reads as if written for each person.
Ready to see it in your own console?
Posting and reviewing are free. Every stage, e-mail and export described here is in the console from the first sign-in.