A feature specific to Google Ads. When you select to utilise enhanced bidding, you’re giving Google the power to adjust your bidding in order to increase conversions. With this feature, you can pay up to 30% over the keyword bid that you set.
Think of it like a hybrid between CPC & CPA bidding, albeit still more heavily weighted toward cost per click. Be careful with enhanced bidding – many search engine marketers will tell you that they have had poor experiences with cost per acquisition bidding within Google Ads.