Marketing covers campaigns and what happened after they were sent.
What it shows
Sends, opens and click-throughs per campaign.
Attribution
Opens and clicks are tracked through the links in the message, so you can follow a click into the product and see what that person did next rather than stopping at the click.
Reading open rates
Treat them as directional. Mail clients prefetch images, which inflates opens. Clicks are the more honest signal, and behaviour after the click is the honest one.