When user query a term, google will search for ads in database than display relevant ads depending upon the keywords present in query. These ads are shown on top & bottom part of the google page or on other websites. These ads are run using advertising platform, Google AdWords.Using Google AdWords you can run display ads, video ads, shopping ads, Search ads, app promotion ads or can drive traffic to your website. To create ads on AdWords you have to pay charges. Depending on bidding google will decide where and when your ads will display.