The Ad Server, Term by Term

A marketplace that runs auctions between many buyers for many sellers’ impressions.

A sequence of ads played back to back in one break, typical for CTV and audio.

The call a player, page or app makes when a placement is ready to show an ad.

The system that receives an ad request, decides which ad should run, serves it and records what happened.

A URL or snippet placed in a page, app or player that triggers an ad request to a specific placement.

A named placement definition: size, format and where it lives.

A file a site publishes listing which sellers are authorised to sell its inventory.

The party paying for the ad.

A resettable, per-device identifier for advertising, available only where the user allowed it.

A reusable set of bundle IDs used to allow or block inventory.

The ads.txt equivalent for apps, hosted on the developer website listed in the app store.

Comparing bids for one impression and picking the winner.

An ad served into streaming audio, podcasts or radio apps.

The share of requests a partner answered with a bid.

The OpenRTB message an ad server sends to a partner describing one impression for sale.

A partner’s answer to a bid request: a price, a creative and the terms of the bid.

The store identifier of an app, used to name in-app and CTV inventory in a bid request.

A random value added to a tag or pixel URL so caches never serve a stale response.

An advertiser’s buy: a budget, a flight and a set of line items that deliver it.

A complete record of one request: signals in, rules applied, partners called, bids back, winner served.

Television content delivered over the internet to smart TVs, streaming sticks and consoles.

An encoded record of the user’s privacy choices, carried in the request under the IAB Transparency and Consent Framework.

Rules based on what the ad will run next to: genre, rating, channel, show.

Cost per thousand impressions. The unit most display, video and audio inventory is priced in.

The ad itself: the video, image, audio or markup that renders.

A rule that stops specific advertisers, categories or creatives from ever serving on a placement.

Requests originating from server IP ranges rather than consumer networks.

An identifier carried in a bid request that tells a buyer a private deal applies to this impression.

The moment the ad server picks the winner for one request, in real time.

The buy side: any source that can answer a request with an ad and a price.

A specific demand source attached to inventory, with its own endpoint, rules and reports.

Software buyers use to bid on impressions across many sources in real time.

Inventory sold by the publisher to an advertiser without an open auction.

The gap between two systems’ counts of the same thing.

A reusable set of web domains used to allow or block inventory.

Effective CPM: revenue divided by impressions, times a thousand, regardless of how the deal was priced.

Impressions divided by requests. What share of the inventory actually served an ad.

The minimum CPM a placement or partner will accept. Bids below it lose, whoever made them.

A limit on how many times one user or device sees the same ad in a period.

Allowing or blocking requests by country, region or postal code.

The IAB framework that carries privacy signals for multiple jurisdictions in one string, including US state laws.

Asking several buyers for bids in parallel before the ad server decides, instead of one after another.

A publisher’s own creative, served when nothing paid fills.

One ad rendered on a screen, counted when the creative actually appears.

Inventory inside a mobile or tablet application.

Requests or impressions that do not come from a real person on a real device: bots, datacenters, spoofed apps.

The ad placements a publisher has available to sell.

A deliverable unit of a campaign: what to serve, where, at what price, how fast, until when.

A placeholder in a tag that the integration replaces with a real value at call time.

A request that ended without an ad being served.

The price a partner actually carried in its bid, as opposed to the price it declared for billing.

The IAB standard for third-party viewability and verification measurement inside apps and players.

The IAB Tech Lab protocol for real-time bidding: a JSON bid request and bid response.

Spreading a line item’s delivery evenly across its flight instead of spending the budget as fast as possible.

A specific ad position: this slot, on this screen, in this format.

The open-source header bidding framework, in the browser (Prebid.js) or server-side (Prebid Server).

The order in which demand sources are considered when more than one can fill.

An invitation-only auction on selected inventory, identified by a deal ID.

A direct deal with a fixed price and volume, delivered through the programmatic pipe.

The owner of an audience and the inventory that reaches it: a site, an app, a channel.

A limit on how many requests per second a partner receives.

Video playback milestones: start, 25%, 50%, 75%, complete.

Matching reported numbers to billed numbers, and explaining every difference.

The creative actually appearing on screen after the ad server returned it.

A daily or periodic ceiling on the requests sent to a partner or served from a placement.

A pricing model where the platform takes an agreed percentage of what the inventory earns.

A file an ad system publishes listing the sellers it represents, so buyers can see who is behind an impression.

Stitching ads into a video stream on the server, so the player receives one continuous stream.

Forwarding what the request carried to demand as received, without stripping or inventing values.

Misrepresenting inventory: claiming a request comes from an app, site or device it does not.

The sell side: publishers and the placements they bring to market.

A field in the bid request listing every party that handled the impression on its way to the buyer.

A platform that aggregates publisher inventory and sells it to many buyers.

Rules that decide which requests a placement or partner is allowed to serve.

The time limit a request or partner call is allowed before it is abandoned.

The maximum time, in milliseconds, a bid request gives a bidder to respond.

A tiny request the player or page fires to record an event: impression, click, quartile, complete.

Video Ad Serving Template: the XML format that tells a player which video to play and which events to fire.

Third-party measurement of viewability, brand safety and invalid traffic on served ads.

Completed video views divided by starts.

An impression that met a visibility threshold, such as half the pixels on screen for one second (two for video).

An older standard that let a video ad run its own code inside the player, for interactivity and measurement.

Calling demand sources in order of priority and stopping at the first one that fills.

The share of a partner’s bids that won the decision.

A VAST response that points to another VAST URL instead of containing the creative itself.