Jargon Buster

Full list of terms title


VAST or ‘Video Ad-Serving Template’ provides a common ad response format for video players that enables video ads to be served on all compliant video players. This means that advertisers don’t need to integrate lots of different ad tags to be able to serve their video across multiple publishers. For more information about VAST see here.

Video On Demand (VOD)

Allows users to watch what they want, when they want. This can be either ‘pay per view’ or a free service usually funded by advertising. All major broadcasters offer VOD such on platforms such as 40D or BBC iplayer. 


Viewability is an online advertising metric that aims to determine only impressions that had the opportunity to be seen by users. For example, if an ad is loaded at the bottom of a webpage but a user doesn't scroll down far enough to see it, that impression would not be deemed viewable. Viewability is not a measure of ad effectiveness.

Viewable Impressions

A digital ad that had the opportunity to be seen, sometimes referred to through the traditional print media term of being “above the fold”. The current industry criteria for a standard ad unit to be considered viewable is that 50% of the canvas was within the consumer’s rendered window for a minimum of 1 second – the time required for a consumer to understand that the unit is a piece of advertising. Viewability is not a measure of ad effectiveness.

Virtual Reality (VR)

Virtual reality or virtual realities (VR), also known as immersive multimedia or computer-simulated reality, is a computer technology that replicates an environment, real or imagined, and simulates a user's physical presence and environment.