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The Glossary is a listing of media related terms found throughout this site, and used in the daily buying and selling of media.

a.k.a Impression Tracker

A 1x1 is used to count impressions. Most often, a 1x1 is provided by an advertiser or agency to a publisher to track site-served creatives that are not hosted by the agency's ad server. Technically, a 1x1 is an image file with dimensions of 1 pixel by 1 pixel. More recently, image files have been replace by Javascript code that can more intelligently track impressions rather than simply activating when an ad is loaded.

An ad server is software used by advertisers, agencies, or publishers to host creative files, deliver ad media and track ad performance. Ad servers function both as media delivery systems as well as analytics and reporting engines. Common ad serving systems are DoubleClick for Publishers and Freewheel (for publishers), and DoubleClick Campaign Manager and Sizmek (for advertisers).

a.k.a Ad Specifications

Ad specs are the technical details that describe the visual, audio, behavioral and delivery characteristics of an ad unit or media placement. Ad specs include dimensions (eg. pixels), file formats (eg. JPG), codecs, frame rates, animation lengths, buttons, permitted colors, content limitations, expansion directions, timer requirements, lead times, frequency caps, and other details. Ad specs are needed for creative teams to accurately build ad units that comply with publisher requirements.

An ad tag is a small piece of computer code that represents an ad unit hosted by a third party. A tag is essentially a pointing device that is most typically delivered by an advertiser to a publisher. The benefit of using an ad tag versus a creative file (eg. JPG, GIF) is should the creative require updating during an active campaign, the advertiser can swap in new creative assets without delivering a new file to the publisher. The tag is simply repointed to the new creative files.

A banner ad is a commonly used ad unit that is rectangular in shape, and is positioned within page content. Most banner ad units are standardized based on IAB specifications, and are widely accepted by both direct and programmatic buyers and sellers. Common banner ad sizes are 300x250 (medium rectangle), 728x90 (leaderboard), 160x600 (skyscraper), 300x600 (half page), 970x150, 970x250, and 320x50.

a.k.a Adhesion Unit

A catfish unit, otherwise known as adhesion or mobile adhesion, is an ad unit that anchors to the bottom of a user's browser window and does not scroll. The unit stays in place and is visible as a user scrolls through page content.

A click tracker is a special URL (eg. used to count clicks by a third party. Typically, advertisers provide click trackers to publishers in order to count clicks on site-served ad units. A click tracker redirects the user to the final destination and counts the click in the redirection process.

A codec is a software algorithm that compresses or decompresses a digital data stream or signal. Codecs are typically represented by file extensions (eg. MP4, MP3, JPG) or other notation such as H.264 for video files. Correctly specifying codecs is important for advertising so media files can be compressed when created by designers, and correctly decompressed by media players on websites and in apps.

a.k.a CTA

A call-to-action (CTA) is a term used to describe the action an advertiser desires be taken by a user when an ad is viewed. Common calls-to-action are "buy now", "get tickets", and "learn more." A clear and prominent call-to-action is a best practice for ad unit design.

Display advertising is a broad term that refers to digital advertising on websites and mobile apps using both in-page and out-of-page formats. Display is often used interchangeably with banner advertising.

a.k.a Slide-out

An expandable ad unit is a rich media display unit that expands horizontally from a closed state to an open state. Typically expandables cover page content in the open state. The open action can be automatic or prompted by the user.

a.k.a FPS

Frames per second (FPS) is a video term used to describe the number of video frames contained within one second of video playback. The higher the FPS number, the higher the quality of video. Most common video is 30 FPS, but ranges can vary depending on the network speed and other factors.

Frequency cap is the number of times that a unique user is served an ad in a given time period. For example, a "1x per day frequency cap" means that a unique user will only be shown an ad once per day.

An iFrame is computer code that is designed to isolate elements on web pages. When an ad tag or creative asset is nested within iFrame code, it is isolated from communication with other elements on the page.

a.k.a Video Progressive

Used most often for branding and awareness campaigns, an in-banner video ad is a banner ad that plays a video within the boundaries of the banner dimensions. In-banner video is played in-page and not in a video player (in-stream), so the value of in-banner video is widely accepted to be less than in-stream video. The IAB includes in-banner video within its standard spec categories.

In-page refers to an ad unit that exists within the page content. Common forms of in-page ads are banners and native ads.

In-stream refers to video ads that are served before, during, or after video content. The ads are served within the same video player, similar to how television ads are served.

a.k.a IAB

The IAB is a membership association comprised mainly of media owners (publishers). The IAB establishes standards, convenes industry events, and serves as the de facto voice for media companies and their interests.

Interstitial ads are served between page views and exist on their own page. Not to be confused with overlay ads that appear on top of page content, interstitial ads are served with 100% share of voice as a user transitions from one page view to another.

a.k.a IO

An insertion order, or "IO" as more commonly known, is an agreement between an advertiser and publisher that describes terms of sale, and other details related to the purchase of media.

a.k.a LCD Spec Sheet

The LCD spec sheet is a consolidated table of the creative assets required to completely fulfill all media placements. The LCD is typically compiled by the advertiser based on the various creative specs submitted by publishers during the buying process. The LCD is given to the creative agency as a guide.

A video ad that interrupts content playback. An example of a linear video ad is a television commercial or pre-roll video ad.

An in-stream video ad that runs in a player during video content (not before or after). Mid-roll is similar to the television commercial format.

A native ad is an in-page ad format that follows the user experience of the content in which the ad is placed.

A video ad that does not interrupt content playback. An example of a non-linear video ad is a video ad that runs over the top of a portion of video content in a player (picture-in-picture).

a.k.a Pop-up Ad

An out-of-page ad unit is an ad placed outside of the page content, often over the top of the content. Pop-up ads are a commonly used out-of-page format.

Out-stream refers to video ads that are not served within video content, rather they are served independently in a player with no accompanying video content. Out-stream video ads may appear in-page or out-of-page.

An overlay ad unit appears over the top of page content. Often overlay ads require the user to close the unit or wait for a timer to expire in order to return to page content. Overlay ads are different from interstitials in that overlays are not between pages, rather on the page being currently viewed. Overlays are a form of out-of-page ad unit.

A pre-roll video ad is an in-stream ad unit that is served in a player before video content.

a.k.a Programmatic Private Marketplace

A programmatic private marketplace (PMP) is a way for publishers to sell reserved inventory programmatically with a specific group of buyers that are pre-qualified to gain access.

Programmatic advertising is a broad term that describes that automated buying and selling of media, where transactions can take place based on pre-defined rules without the intervention of people.

a.k.a Pushdown

A pushdown ad unit is a rich media display unit that expands vertically from a closed state to an open state, and pushes down the page content during expansion. The open action can be automatic or prompted by the user.

Rich media is a type of display advertising that exists beyond the ad unit dimensions. Rich media can expand over the top of page content in the case of expandables, or move page content in the case of pushdowns. Rich media can also provide the user with richer media experiences such as full-screen video, or other functions such as gyroscope interaction for mobile rich media and gaming experiences.

a.k.a Hover State

Roll-over refers to the change of an ad's state when the user's mouse pointer or other touch device is present over the ad area. Roll-overs are most commonly used to change button colors to drive higher ad engagement and click-through.

a.k.a RTB

RTB refers to the process within programmatic advertising by which advertisers bid for publisher ad inventory in an automated auction. RTB is based on specifications defined by the IAB.

a.k.a First Party Served Ads

Site-served ads are hosted by the publisher or media owner and served by the publisher's ad server software.

Tag wrapping refers to the process by which a third party embeds an ad tag or creative within computer code for tracking and reporting purposes. Tag wrapping is often performed by ad-tech vendors prior to delivery of tags to publishers for measuring performance along dimensions such as viewability, deliverability, engagement, and impression count accuracy.

A test page is a URL delivered by a publisher to an advertiser or agency that shows a mock-up of a site, app or other content. Test pages are used to gain approval by advertisers of more complex ad executions prior to flight.

a.k.a Ad Calls

Third party served refers to ad creative that is hosted and served by an advertiser or agency based on a request (an ad call) by a publisher's ad server. In this scenario, ad tags are delivered to publishers prior to flight.

a.k.a Universal Placement Identifier

A universal placement identifier (UPID) is a globally unique code assigned to a media placement. UPID codes are designed to simplify the buying and selling of media by creating a simple code that refers to a unique media placement. A UPID is created by adding a new media product to

Viewability is a measure used to describe the percentage of ad impressions actually seen by real users.