The ad creative types refer to the different kinds of banner ads that can be used on the websites. They are generally rectangular in shape and are broadly categorized as the skyscraper banner ads and the leaderboard banner ads. The have a set size and the advertiser can design the banner within the given peripherals. The skyscraper banner ads are of 120 X 600 or 160 X600 in case of a wide skyscraper ad. They run towards the length of the webpage. In other words they are vertical ads that can be placed on the left side or the right side of the page. The leader board ads on the other hand have standard size of 728 X 90 pixels and cover the width of the webpage. It can be placed on the top of the webpage or on the bottom as per the advertiser and the space the publisher has sold.
Apart from this you can get other kinds of banner ads also which have different sizes. The IAB has given out the standard size for the banner ads and you can easily choose the size that meets your requirement. Most of the advertisers prefer to use leaderboard and the wide skyscraper or opt for ads with 300 X250 pixels.