The main differences between Google Search and the Google Display Network is that Google Search uses text-based ads that appear on search engine results pages of Google and its partner websites. These ads reach end users through the keywords they use in their search queries.
The Google Display Network displays ads in various areas of a webpage (e.g. banner or sidebar) with these ads showing up across a vast number of third party sites on Google’s network, as well as Google’s own platforms like Gmail. These ads can contain graphics, images and even animated elements and reach people browsing the network depending on parameters such as demographic, interest, and activity.