Pause – A video, animation or audio control that enables users to stop the video, animation, or audio from playing until the user is ready to resume play.

Pixel (as a unit of measure) – The smallest unit of measure for graphical elements in digital imagery, used as the standard unit of measure for ad creative (i.e. 300×250 pixels). Pixels may also represent x/y coordinates relevant to a given space, such as the browser window, an application workspace or the user’s computer screen. (See also “Tracking Pixel”)

Pixel Density – The number of pixels displayed on the screen within an inch (pixels per inch or PPI) or within a centimeter (pixels per centimeter or PPCM). Screen pixel density varies by device with older monitors displaying 67 – 130 PPI. Mobile devices often exceed that at 300+ PPI. Pixel density of 163 PPI is referred to as pixel density of 1 in this document.

Play – A video, animation or audio control that enables a user to initiate (or avoid initiating) the video, animation or audio of an ad.

Polite file load – Withholding a portion of the total ad creative file size (besides any initial file load size) from loading on a page until publisher content has loaded. With the release of the Display Creative Guidelines in 2015, polite file load has been replaced “Host-initiated subload.” See Host-Initiated Subload for definition.

Pop-up Ad – Any advertising experience where visiting a website in an initial browser window initiates a secondary browser window to deliver an ad impression directly above the initial browser window.

Portrait – An IAB Rising Star ad unit template that uses up to three interactive modules chosen (by the ad designer) from a variety of modular application options in a 350×1050 pixel space.

Progress Bar – A video or animation control that shows users the progression of the video or animation in relation to its total duration.

Progressive Load Video -A distribution method for serving video files in which the video file downloads progressively into the cache of a user’s computer, much the same way images and other content elements are downloaded. HTML5 files use progressive download for video files, but streaming methods can be simulated using adaptive bit streaming technologies such as HLS and MPEG-DASH.

Pushdown – An IAB Rising Star ad unit template designed for rich interaction in a space similar to, but larger than, an expanding leaderboard, with initial dimensions of 970×90 pixels and expanded dimensions of 970×415 pixels. When the ad is expanded, it “pushes” page content down rather than displaying over the top of page content as most expandable ads do.