What are website Ads?
Website ads are digital display advertising that appear at the tops, bottoms and sides of websites. At the time of writing, website ads still come in a few standard, predetermined pixel sizes but things are changing. In other words, if you were to create a standard suite of banners today, it would probably mean that you were making between 3-9 different sized banners. Depending on their size, those banners would have a different position on the users webpage. With the larger, more premium banners sitting at the top of the page, such as the Billboard (970×250) and less prominent or premium banners like the skyscrapers (160×600) at the sides of the webpage.
With the above in mind, it is probably worth noting that ad industry standards are always changing. The Internet Advertising Bureau (IAB) has recently proposed a new set flexible banners under their LEAN initiative. These banners would resize to fit any particular placement – so instead of creating a whole host of fixed size banners, you might only create one or two ads that resize dynamically (portrait, landscape, mobile).