Advertistments are placed on Google Search Results at either the top of the page or in the right hand column. Sometimes they are also repeated at the bottom of the page.
Google's Product Search which had offered free listings for comparision shopping has now become Google Shopping and companies will now be charged for the listings. The listings on Google Shopping which are called Product Listings Ads use AdWords. To create Product Listing Ads, you’ll need to have an AdWords account and a Merchant Center account.
Types of Display Ads
Display Ads are placed on websites The advertiser has access to The Display Ad Builder where they have a choice from hundreds of templates, colors, fonts and stock images. They are also have the option to combine their own images.
Text Ads: The copy for these ads is the same as ads placed on Google's search results. They include a headline, two lines of text (35 characters each), and a URL.
Image Ads: Images that contain customized layouts, design and copy
Rich Media Ads: Can have interactive elements, animation and can change depending upon the user