Google AdWords is Google's online advertising platform that generates 96% of Google's revenue. It is divided into search and display networks. The search network includes Google.com and partner sites that only support text ads, while the display network supports different ad formats on over 300 million partner websites. AdWords uses an auction system and quality score, which factors like click-through rate and landing page quality, to determine ad rank and position. Higher ad rank means higher position and more clicks and traffic for advertisers.