A banner ad is a rectangular internet display advertising format which drives visitors to a post-click landing page when clicked. Common web banners and sizes are:

Full banner: 468×60

Half banner: 234×60

Vertical banner: 120×240

Leaderboard: 728×90

How Does banner ads work?

By collecting data from a browser's cookies, advertising venues can access information from a Web surfer's browser to display ads corresponding to the surfer's previously expressed interests, allowing advertisers to target specific demographics. An affiliated advertising broker's software can therefore display an advertisement that the surfer is most likely to click.