Sent
Number of subscribers the campaign was successfully sent to

Opened (unique)
Percentage of total recipients (successful deliveries) who opened the campaign.

Clicked (unique)
Percentage of total recipients who clicked any link that is relevant in the campaign.(Note: A relevant link is a link that is not “Manage preferences”/ “Social” / “Update info” / “Unsubscribe” / “Web version” link)

CTOR (Click To Open Rate)
Percentage of recipients that registered as an open who also clicked a link in your campaign

Deliverability Rate
Percentage of recipients that wasn't hard or soft bounce on this campaign

Bounce Rate (Soft / Hard)
Number of deliveries that registered as a hard or soft bounce

Unsubscribed
Number of subscribers that opted out of your list using the unsubscribe link in this campaign.