Page Impressions: This is the number of people who have viewed your ads on a given day. This number represents all the visitors to your site, whether they stayed on the site or bounced right back off.
Clicks: This column adds the number of times folks have clicked one of your ads.
Page CTR: Short for Page Click-Thru-Rate, Page CTR shows the percentage of people who came to your site and then clicked through your AdSense ads to the advertiser’s page. The higher your percentage, the better your ads are performing.
Page eCPM: Don’t ask me how they get Effect Clicks Per Thousand out of eCPM. (The acronym has something to do with the metric version of measurement, which really doesn’t matter to you one bit.) What you do need to know is that this figure is arrived at by dividing your total earnings by the number of impressions in thousands. For example, if your site earns $100 from 10,000 impressions, your eCPM is $100/10 or $10.
This represents the amount that you’re making per thousand impressions, however, and doesn’t represent exactly how much you’re making. Instead, it’s a measurement that you can use to compare results across channels or advertising programs.
Earnings: The actual amount that you’ve earned over a given timeframe is shown in this column. Specify the timeframe you want to examine with the View drop-down menu. You can view results by Today, Yesterday, Last 7 Days, This Month, Last Month, and All Time.