Video Player Ad-Serving Interface Definition. VAST supports relatively simple in-stream video ad formats that are not executable. VPAID was created to support more interactive rich media video formats. For more information see the Interactive Advertising Bureau (IAB) VPAID documentation.

Video Multiple Ad Playlist (VMAP) specification. This is an XML template that video content owners can use to describe the structure for ad inventory insertion when they don’t control the video player or the content distribution outlet.

A measure of whether an ad has been seen by a given user. Viewability measurement is achieved using javascript embedded within each creative which is then called for each individual ad impression. The script launches automatically as the page loads and immediately starts measuring if and when the creative is viewable based on a variety of measures. These may include whether a web or browser tab is in focus whether a particular ad is in view of a user based on where on the page the user has scrolled to how long an ad was visible based on these metrics and other factors. The most commonly used bidding strategy based on viewability is CPVM. In 2015 the Interactive Advertising Bureau (IAB) released industry standards for viewability. To learn more see the IAB website.

A quartile is 1/4th of something. Media players fire a series of engagement pixels as the video continues to play. These pixels typically indicate how many quartiles of a video has been played firing at 25% 50% 75% and 100% completion.

In online advertising a vendor generally refers to a company with a specific product or service such as creating or delivering rich media maintaining a CDN or providing third-party data.

Video Ad Serving Template. This is an XML-based video ad serving protocol. It was created to provide a uniform way for video content to be transferred from ad servers to video players on web pages. For details see the Interactive Advertising Bureau (IAB) VAST documentation.