A) Display ads
Display ads are the oldest and most used ad format.
Click on the icon of this ad type and start entering a name as suggested in the section above.
Responsive display ads
The most critical choice for Display ads is the one about the size.
AdSense’s recommendation is to use a Responsive ad format, which means that the width and height of the ad will be selected automatically by AdSense. They usually fill out 100% of the available width of the element the ad is placed in. E.g., if your sidebar is 300px wide, the ad will be 300px wide as well. This format is the best choice for responsive themes.Name your ad and choose between a square, horizontal, or vertical layout
Fixed-sized display ads
There are a few situations where you might want to have a fixed ad size. The most common is that AdSense cannot always determine the available with so that the ad space stays unused. Or that you want to float text around an ad, which is also not possible with responsive ad types.
For testing, I’d recommend a 300×250 Medium Rectangle. Go to the Ad Size field at the top right, select Fixed and enter the values for width and height as in the image below.Define a fixed size for your ad unit
Get the code
Click on Create to get the ad’s code.
Advanced Ads will later get the code automatically, so you don’t need to copy it. Jump ahead to this step.