The Terms in Google AdSense

1. Publishers

Publishers are website owners who have joined with Google AdSense and have paired the AdSense ads on your blog or website

2.  Ad Unit

Ad units are one type of AdSense ad, ad unit consists of several types and sizes. The most common type of ad text. When visitors click the ad unit and the clicks were valid, publishers will get revenue in accordance with the price per click or CPC (Cost Per Click).

3. Link Unit

Unit link similar to ad units. The format is similar to the usual format of the menu we encountered on few web sites. What distinguishes the unit link with ad units are direction of targeted visitor number after visitor number click a link.

4.  AdSense for Content 

Is AdSense for content are AdSense ads posted on a page. The ads that came are the advertisements that relate to these pages or phrase using contextual concept. Ad units and link units includes AdSense for content. 
 5.  Alternate Ads
If the advertising inventory relating to thecontents of of a site is up or Google can not predict contents of sites ,by default ,Google shows public service ads or commonly known as the PSA ( PublicService Ads). Because the type of donation, click on the public service ads are not produce anything for publishers. To overcome this, Google allows publishers to display the alternate ad. How, publishers do the settings of your ad units using alternative ads.
to be continue....