The term ‘display ad’ is a blanket term for adverts that can be defined in three different categories. These are site placement advertising whereby your ads are placed onto third party websites; Contextual advertising where networks place their ads on what they believe to be relevant websites i.e. an ad for cat food on a cat rescue website and lastly, Remarketing. Remarketing in short, is where display ads appear in front of previous visitors, to your site or landing pages, whom have left without converting.