A Demand-Side Platform (DSP) is a technology that allows advertisers to purchase digital advertising space in an automated way. It enables marketers to manage multiple ad exchanges and data sources through a single interface, making it easier to target specific audiences and optimize ad campaigns in real-time. DSPs use algorithms and data analytics to help advertisers reach their desired audience more effectively. By analyzing user behavior and preferences, a DSP can bid on ad inventory across various platforms, ensuring that ads are shown to the right people at the right time, ultimately improving return on investment (ROI).