Direct, Native, and Programmatic refer to “Ad Channels”.
Direct (also know as “direct buys”) are placements purchased directly from publisher sites, bypassing ad networks and exchanges.
Native ads are placements purchased via native ad networks like Outbrain or Taboola. These ad units are usually designed to look more like “additional content” than a traditional ad normally would.
Programmatic ads are display ads that don’t fall into the Direct or Native channels. They are placements purchased via traditional ad networks and exchanges.