The main difference between an email template and an email campaign is that a template is the foundation and layout of an email preset and a campaign is an actual email message that is sent out and delivered.
The email template is a preset layout you build your campaign on. It can be useful because it saves you time when creating the emails for your subscribers. If you plan to send the same layout more than once in the future, you might consider creating an email template.
This is an example of what an template may look like:
An email campaign is the email message you write and design, and send to your specific contact(s) or a list. You can edit the template layout you already have to edit text, images, backgrounds, to mention a few.
This is an example of an email campaign after the info from the template has been customize for a specific email:
