Duplicating a campaign will automatically turn the campaign into a draft. While creating a template allows you to view exactly which campaign you want to send out without having to open the file
Select Marketing > Email Marketing > Campaigns
Under the all section hover over any of the campaigns that you want to duplicate or create a template for and select the grey dropdown next to the campaign.
The user can then decide to select "Duplicate" to create a draft or click on "Create a Template"
If you created a Template campaign, you will find the campaign under "Templates"
If you created a duplicate campaign, you will find the duplicate under the "Drafts" section.