If you're not sure what all that Google AdSense jargon means, you're not alone. Fortunately, the Google team has your back. A Google AdSense Glossary has been posted to Google and covers everything from account type to ad display terms to reports to technical terms.
The CPC is the amount an advertiser pays each time a user clicks on his/her ad. Google AdWords has a CPC pricing system.
And like other "help" documents on Google's site, you can provide feedback to Google to inform them about whether the information given is helpful or not so that they can continue to release a product that addresses everyone's satisfaction.