The email delivery page is where you can view statistics for opened, unopened, bounced, and unsubscribed emails for a campaign.
You can view the percentage of opened, unopened, unsubscribed, and bounced emails on the pie chart that is to the left of the page. You can see the statistics for different campaigns by clicking the drop down menu that is located above the pie chart, and selecting the campaign you would like to see statistics for.
You can click on a piece of the pie chart to view which recipients fall into that category. For example, to see who opened the email, click on the Opened slice of pie. The grid on the right will populate with all recipients that opened the email.