Glossaryvideo advertisingad serving

VAST (Video Ad Serving Template)

VASTIABvideo playerin-stream video adsad serverXMLindustry standardYouTubedesktopmobiletablet

An XML schema developed by the IAB that standardizes how in-stream video ads — the kind that play inside a video player, like ads served on YouTube videos — are delivered from video ad servers and rendered across video players on multiple websites and publishers. VAST supports playback on a wide range of device types, including desktop, mobile, and tablet.

The standard was adopted to resolve compatibility problems that arose when video ad servers and the video players embedded on publisher websites couldn't communicate in a consistent way. By defining a common schema, VAST lets a single video ad creative be trafficked once and served reliably wherever a compliant player exists.

VMAP (Video Multiple Ad Playlist)
VMAP allows content owners to describe the structure for ad-inventory insertion when they do not control the video player themselves — as is the case on platforms like YouTube, where creators upload content but have no…
Ad Call
Also known as: ad request An ad call is a request sent from an ad slot on a web page or app to an AdTech platform — typically an ad exchange or ad server — for the purpose of serving an ad to the user. Ad calls usually…
Ad Slot
An ad slot is the physical space on a webpage where ads appear. Publishers place ad slots in strategic locations across their site — typically areas where ad visibility and engagement are highest. Each ad slot contains…
Ad Tag
A piece of code inserted into an ad slot in order to display an ad. When a web page or mobile app loads, the ad tag requests the necessary information and carries out the processes required to render the creative.…