The main difference between automation emails and campaign emails is: 

1. Campaign emails will be sent as a "one-off" email. This means, you would use campaigns for newsletters, specific promo sales sequences, etc. 

2. Automation emails are used in automations when something has been triggered. For example, these are your confirmation emails after someone has purchased a product and/or service from you, a follow up after a call booking, email reminders for call bookings, the list goes on. 

Go here to get you started using automated emails:

Automated email reminders after someone books a call

Automated email confirmations after someone purchases from you