In the context of display advertising, a content-delivery network (CDN) can be used to deliver ads to users more efficiently. This can help to improve the performance of the ads and reduce the amount of time it takes for them to load on a user's device. CDNs can also help to ensure that the ads are delivered to the right users based on their geographic location. Additionally, CDNs can provide various security and privacy features to protect the ads and the user's data. For example, CDNs may use encryption to protect the ads from being intercepted and may also provide tools to help advertisers comply with various privacy regulations.