Ad inventory refers to the advertising space available for purchase by advertisers from publishers. This space encompasses various digital platforms like websites, mobile apps, videos, and games, along with traditional media. The value of ad inventory is determined by factors such as traffic volume, with prime spots like homepage placements considered highly desirable. Ad inventory can be sold programmatically through exchanges or auctions, supporting different ad formats like banners, videos, and playable ads. Publishers can sell ad inventory directly or use intermediaries like networks or exchanges. It’s worth noting that ad inventory isn’t limited to websites and includes in-app ads, connected TV (CTV) streaming, and over-the-top (OTT) TV streaming apps.