Types of zone tag
A zone tag is the code chunk that places your ad item on a page. It passes along the ad item information, and usually some extra information, for tracking and display.
Choosing the right type is important because, depending on the situation, your ad item may not show or you may miss some features if the zone isn’t properly configured. See below for a breakdown of characteristics for each different zone tag.
Asynchronous 1.1 (Beta)
This is particularly useful in cases like infinite scrolling sites where document.write may cause conflicts with white pages or empty spots.
iFrame & iFrame (HTML Only)
This will serve an HTML image tag wrapped in a hyperlink tag to direct users when they click.
JSON Ad API
These tags are lightweight, easy to use, and are AMP compliant to allow mobile sites to load as quickly as possible. There are two cases where you'll have to modify your AMP tags before they can serve, which you can read about here.