What is the difference between real-time bidding and programmatic buying?

Real-time bidding (RTB) is a subset of programmatic buying; it’s the technology that allows for the instant, auction-based purchasing of individual ad impressions, optimizing for price and targeting.

Programmatic buying, on the other hand, is a broader term that refers to the automated purchase of advertising space, whether through real-time auctions or other transaction models like private marketplaces or programmatic direct deals.

The key difference is that RTB is a specific buying mechanism within the wider programmatic advertising ecosystem.