An ad unit is one or more Google ads displayed as a result of one piece of the AdSense ad code. You can create, customize and manage ad units on the Ads page in your AdSense account. Ad units give you control over where ads appear, and our native ad units offer lots of flexibility in terms of customization.
Types of ad unit
AdSense offers several different types of ad unit. If a display ad unit doesn't meet the requirements of your site, consider using one of our more specialized ad units: