A completed template is a "filled envelope" of training content. When rolled out, each employee receives his/her own training content - "the envelope" is copied 1:1, so to speak, with the difference that the type changes from "Template" to "Usage" and the owner becomes the respective employee.
When you create a certificate / skill level / training plan / training / learning module or exam, you automatically start with the type "template". Ideally, you should never manually set the type to "Usage", as this is automatically adopted via the Rollout Center.
This functionality becomes available as a Preview Feature with Rollup Update 42.