Automation emails are singular emails that are contained in Workflows, Rules, and Bulk Operations. When an Automation email is created it becomes exclusive to the Workflow, Rule, or Bulk Operations where it's being utilized and it's not possible to transfer an Automation email between features.
Place Automation emails at desired points throughout a Workflow. This provides a way to send a singular email after a trigger is engaged by a person.
Send an Automation email to a person once a Rule's trigger is engaged.
Manually send an Automation email to a segment of people either immediately or schedule it for another time.