A sell side platform (SSP) is a technology platform that enables publishers to sell their digital advertising inventory to advertisers and agencies. It acts as a middleman between publishers and advertisers, providing a streamlined and efficient process for buying and selling ad space. The SSP allows publishers to manage and optimize their ad inventory, set pricing, and connect with a wide range of potential buyers. It also provides real-time bidding capabilities, allowing advertisers to bid on ad space in real-time, resulting in more targeted and effective advertising campaigns. In short, the sell side platform is a crucial tool for publishers to maximize their revenue and for advertisers to reach their desired audience.