Internet advertising inventory refers to the available space on websites, social media platforms, and other online channels that can be used for displaying advertisements. This includes banner ads, pop-ups, sponsored content, and other forms of digital advertising. The term is often used by advertisers and publishers to describe the amount of ad space that is available for purchase or placement. As the demand for online advertising continues to grow, the value of internet advertising inventory has also increased, making it a key factor in the success of digital marketing campaigns.