The document discusses the core components of adtech which plays a fundamental role in digital advertising. It describes demand-side platforms which allow advertisers to purchase ad inventory, supply-side platforms which allow publishers to sell ad inventory, ad exchanges which are marketplaces where advertisers and publishers transact ad inventory through auctions, data management platforms which collect and analyze audience data to optimize ad targeting, and ad servers which deliver ads to users' devices. Understanding these core components can help marketers and advertisers navigate digital advertising effectively.