Adwords is an advertisement by the google business. The ad service is largely focused on keywords.

Google AdWords is the system Google has developed to assist you in marketing your products or services in the Google Search Engine, and its affiliate sites, via the use of a placed text ad that appears when people search for phrases related to your offering.

Google AdWords is an online advertising service, developed by Google, where advertisers pay to display brief advertising copy to web users.

See google AdWords is the ad platform between investor of the ad and google. In this platform investor has to pay for google to promote his ads via google search engine results.