Visitors - number of unique visitors on your website

Engaged Visitors - number of unique visitors who saw at least one notification

Engagement Ratio - ratio of users who visited your website and saw at least one notification

Impressions - number of times your notifications have been viewed (7 day unique impressions)

Hovers - number of visitors who hovered your notifications (7 day unique hovers)

Clicks - number of visitors who hovered your notifications (7 day unique hovers)

CTR - ratio of users who saw a notification and clicked on it (clicks divided by impressions)