Vast

VAST (Video Ad Serving Template) is a specification defined and released by the Interactive Advertising Bureau (IAB) that sets a standard for communication requirements between ad servers and video players in order to present video ads.

It is a data structure declared using XML.

VAST has 8 versions: 1.0 (deprecated), 1.1 (deprecated),[1] 2.0, 2.0.1(The schema version as the official VAST 2.0 schema)[2], 3.0[3], 4.0[4], 4.1 and 4.2.