Opened means someone has opened the mail (hopefully to read it). This statistic does not include emails that have been read in preview mode. The best way to treat "Opens" is to look at trends and remember they will actually be higher than recorded.
The total number of times your campaign was viewed by your recipients. This means that if you send a campaign to 2 recipients and one reads your email twice while the other reads it once, the total opened will be 3.
The unique opened does not take repeat opens into account, meaning the figure represents the total number of recipients that actually opened your campaign.
The Clicks data provides a number of important figures about the links in your campaign. As an example, "2,481 (14.28%) recipients clicked 7 links" tells us the following:
A total of 2,481 recipients clicked at least one link.
This resulted in a click-through rate of 14.28%.
All up, 7 different links in the campaign were clicked.
It may be a link to your website or an extension of the article in the newsletter. You can deliberately encourage "clicks" by putting a summary of the article in the newsletter with a link to the full article residing on your website or blog.