AdSense Vocabulary: A List of the Most Common Ones

Page Impressions
Page impression is how many of your pages were looked at by people. When somebody goes to your website and loads a page in their web browser, Google counts that as one page impression. If that same person browses around and looks at 10 pages of your site, Google counts that as 10 page impressions.
Page CTR (Click Through Rate)
CTR is the number of clicks an ad unit receives divided by the number of times the ad unit is shown (impressions). For example, if you had 1,000 page impressions, and those 1,000 page impressions resulted in 100 clicks on the ads, that is a 10% Page CTR (100/1000 = 10%).
Page eCPM (effective Cost Per Millie)
It means cost per 1000 impressions (millie). From a publisher's perspective, CPM is a useful way to compare revenue across different channels and advertising programs. It is calculated by dividing total earnings by the number of impressions in thousands. For example, if a publisher earned $180 from 45,000 impressions, the CPM would equal $180/45, or $4.00. With AdSense, eCPM is telling you how much you will earn for every 1,000 page impressions. If you have a $4 eCPM, that means you will earn $4 in clicks for every 1,000 page impressions on your site.
EPC (Earnings Per Click)
It means how much you earn for each click. This term will not appear in Google AdSense reports, but you’ll hear it a lot if you visit forums about AdSense.
Channels
Google provides channels so you can analyze each pages, sites, and domains to see where your money is coming from.