Ad Banner
A graphical web advertising unit on a webpage or email newsletter. Ad banners can be created in various sizes and many companies advertise on the major search engines using banners. Here are the specs allowed by the ‘Big 3′:
You might find that different search engines and portals require different sizes and formats for ad banners, but the links above should provide an example of what type of banners and banner placement options you have on the major search engines.