Floodlight is a system Search Ads 360 and Campaign Manager 360 use to track and report conversions.
A Floodlight tag is an iframe or image tag that you install on a conversion page in the advertiser's site. When a customer lands on the conversion page, the tag sends data about the conversion to Search Ads 360 and Campaign Manager 360. The conversion data is stored in a Floodlight activity, which you can include in reports.
With the changes across the web that affect conversion measurement, we recommend that all customers move to the Google tag, a site-wide conversion tag. The Google tag makes implementing Floodlight tracking easier. You'll also benefit from the latest dynamic features and integrations as they become available. Learn more about how to use the Google tag format in your Floodlight activities.