Google AdWords is an online advertising service.
Google AdWords lets advertisers set a budget for advertising, with the advertiser only charged when the ads are clicked or when a conversion or impression goal is met. The service lets users target web users based on predefined keywords chosen by advertisers.
The service offers a choice of advertising options – pay-per-click (PPC), cost-per-acquisition (CPA), cost-per-thousand-impressions, or cost per mile. There are also options for site-targeted advertising for text, banner and rich-media ads, as well as remarketing services.
Advertising via AdWords has become one of Google’s main sources of revenue.