Viewability refers to the measure of whether an online advertisement is actually seen by users. It is determined by factors such as the ad's placement on a webpage, the size of the ad, and how long it remains in the user's view. Advertisers aim for high viewability rates to ensure their messages reach potential customers effectively. In digital marketing, achieving high viewability is crucial for maximizing the return on investment. Various industry standards, such as those set by the Interactive Advertising Bureau (IAB), help define what constitutes a viewable ad. This ensures that advertisers can trust their ad placements are effective.