Enable Selected - By default all Automations are in in disabled status. We wouldn't want you to start sending automations until you are ready to. When you have gone through every step and are ready to move forward click the checkbox next to your automation and click Enable Selected.
Disable Selected - By default all automation are disabled. If you have a running automation and need to stop if for any reason click the checkbox next to the automation, then choose Disable Selected and you will see the status change from Enabled to Disabled.
Actions - Delete - If you ever need to delete an automation you can select the automation checkbox and choose Actions - Delete