Google AdWords is an online advertising service in which an advertiser pay to display the advertisements in google ad network to the web users. It allows to place search results for your website on a search engine results page (SERP) by paying for them.
Each time a user clicks on the ad, advertiser has to pay to Publisher. Google AdWords partly works on the cookies and partly on the keywords selected by the advertiser.
Google's text advertisements are short, consisting of two headlines with a maximum of 30 characters each, a description with a maximum of 80 characters, and a display URL of 40 characters. On Search engine it is nominated as 'Ad' or 'sponsored'.