There are two types of programmatic buying —

• Programmatic direct
• Programmatic RTB

Here programmatic refers to automatic. Ad space  is bought automatically on a web page by two methods — bidding for the space or buying it directly.

Programmatic RTB is like Google AdWords. It is only for display ads, and not for search results.

After RTB, the winning ad appears on the web page. Every time an ad loads, it is considered as one impression. Its price is determined by what buyers are willing to pay in real time. This is facilitated by DSPs. A DSP is a fully automated software that bids impressions from an ad exchange.

Programmatic direct is also called programmatic guaranteed and programmatic premium. It is an automated process of buying guaranteed space without involving in an action.