The statistics are divided in three parts the first one is the global statistics:
When you arrive on this screen the statistics who are displayed are the global statistics for all the campaigns.
If you want to view the statistics of just one campaign you need to change the campaign in the dropdown on the top the page.
In the first part of the statistics you'll have these stats in percentage:
Successfully sent: The percentage of all the mails that could be sent by your sending method (your server / an SMTP service...)
Open rate: The percentage of the mails that have been opened (not 100% reliable as it only works when the user shows images in their mail client, but close to the "real" number)
Click rate: The percentage of the mails in which the user clicked a link (100% reliable this time)
Bounce rate: The percentage of mails that register a bounce (email address does not exist, blocked by filters, etc...)
Unsubscribe rate: The percentage of users which unsubscribed from the email you've selected. If you didn't select any email you won't have this statistic shown.
Devices chart: It shows from which platform the emails have been opened (generally Windows, Mac, iPad, etc...)
Opened with: It shows from which source the emails have been opened. Either the browser (when it's opened with Gmail for example) or the application (Outlook, Thunderbird, etc...). This can be quite useful to know on which source you should test that your emails look good.
This chart shows you through the time line all the number of times that your campaign was opened and clicked.
On the top right corner, you can choose which period you want to see statistics. If you click on the inputs a datepicker should open and then you can pick a date.
On the top left corner of the chart, you can choose to watch data by month, day, or hour. And at the opposite, you can hide one of the data (click, open) if you want.
You can hover the dot to get more information :
This chart shows the percentage of when users opened your emails during the week. With this chart you can have a great indicator of when most of the users open your emails, so you this way you know when to send your campaigns.
You will also see a line chart that shows you when the emails are generally opened in the week so you may choose a better time to send your emails.