Google has two properties where display ads are eligible to appear:
The Google Display Network
The Google Display Network is comprised of Google properties like YouTube, Google Finance, Gmail, and others that offer display advertising, as well as a network of millions of partner sites and mobile apps on which you can place your ads. Google has built out the tools and products needed to help you maximize results from both brand and product awareness campaigns and also direct performance campaigns that use display ads.
Through the Google Display Network, advertisers can access display ad inventory from publisher partners in our Google AdSense program and the DoubleClick Ad Exchange. Using Google Ads or an approved third-party ad server, advertisers can place their text, image, video, or rich media ads automatically on relevant sites across the network. They can run these campaigns across the network by contextually targeting, manually selecting specific topics or placements, remarketing, interest and demographic targeting and more.
Online video and game sites within the Google Display Network are also available to advertisers who want to extend the reach of their display campaigns even further. Advertisers can appear before, during or after a video stream , overlay a video or text ad on top of a video, or run an image, video, or text ad at the conclusion of a video . Ads are sold on an auction pricing model and can be managed through Google Ads by selecting online video and game sites within the network.
Display ads can appear on YouTube in two ways: through an auction-based model using Google Ads, or through a reservation-based model where placements are purchased directly through YouTube ad sales. With Google Ads, you can target your display ads to appear in, on, or around YouTube pages. With reservation-based placements, you have access to different YouTube inventory that is not available through a self-managed Google Ads account, such as the Homepage. Pricing for reserved inventory is based on a pre-determined spend with higher cost commitments and an impressions-based reservation model.