Programmatic advertising utilizes software to automate the purchasing of digital ads, enhancing efficiency compared to traditional buying methods that involve human negotiation. Real-time bidding (RTB) is a subset of programmatic advertising that allows for the purchase of ad impressions through live auctions, targeting specific users based on behavior rather than just website demographics. The document also discusses related technologies, including ad exchanges, data management platforms, and supply-side platforms, which collectively support the evolving landscape of digital advertising.