To see how your Ads and Keywords are performing, click the "Reports" tab, and then click the "Ads and Keywords" page.  From here, you can discover the top performing Ads and Keywords in your PPC Campaigns.  Here, you'll see your clicks and leads per day, your top 5 Ads including the headline copy of each Ad, and your top 10 Keywords including detailed information about each Keyword such as the number of impressions and number of clicks.  An impression is the number of times the Ad was viewed by a person.