An ad network (in the online space) is a company that brings together advertisers (for example, a local dentist) to a website that wants to sell ad space. In the absence of an ad network, a dentist would need to email or call every website where wanted to show an ad. And every website would need to devote resources to negotiating prices, terms and conditions for selling ad space. Both sides benefit by working with an ad network (most commonly, the Google Display Network) to connect advertisers with websites that want to run ads. At the same time, an ad network like the Google Display Network can take on the challenge of providing both a sophisticated targeting system and an easy to use reporting framework.