Last updated on January 11, 2018
An ad unitThe smallest inventory component that represents the space on a site where ads display. is the specific place on your siteAn OpenX component that represents top-level domains or subdomains and is used to organize ad units. Sites enable you to target and report on inventory performance. where you want to display an ad. Create an ad unit for every location on your site where an ad should be served. You can see ad units in at the bottom of the diagram below.
If you're an OpenX Ad ServerA complete digital advertising platform where publishers sell, manage, and deliver their advertising inventory across all digital formats. user and you'd like to see how ad units relate to OpenX Ad Server as a whole, click here or on the diagram below.
Ad unit size
Each standard ad unit is a certain size, measured in pixels. A 728 x 90 ad unit is 728 pixels wide and 90 pixels high. OpenX also supports flexible ad units. Flexible ad units accept creatives of more than one size.
How ad units work
Each ad unit has a unique identifier and belongs to a single site.
When you create an ad unit in OpenX, you will receive an ad tagA small piece of code that defines the ad space where ads display on a website. It includes parameters that describe the inventory advertising campaigns can target, which may in turn display ads in the ad space., a piece of code to put in your website's source code. When a viewer loads the page, the ad tag communicates to OpenX and requests an ad that fits in the space allotted to it. This request is called an ad call. OpenX then finds an eligible ad and sends it to the ad tag. The ad tag puts the ad in the ad unit, and the viewer sees the ad.
For more detailed information on how a specific ad is selected, see Ad selection.
Ad unit inventory types
There are various inventory types for your ad units. Here is a brief explanation of each:
Web: Ads on web pages
Mobile: Ads on mobile webRefers to the use of the Internet via a mobile device web browser, specifically to differentiate from mobile app. pages or within mobile applications
Linear videoAn ad or ad unit that displays in sequence with video content in a video player. Sequencing may be pre-roll, mid-roll, or post-roll. Can be accompanied by a companion ad. An example is a video ad that plays before a video starts, though static images may also serve.: Video ads that play before or during video content in a video player
Non-linear videoAn ad or ad unit that displays on top of video content in a video player. Can be accompanied by a companion ad. An example is a banner that displays at the bottom of the video player while video content plays.: Ads that display within a video player
Video companionAn ad that serves in conjunction with a video ad and is located outside of the video player.: Ads tied to linear or non-linear ads and are displayed outside the video player
Native: Supports a range of custom ad formats expressed using the OpenRTB dynamic native ads API
Are you ready to create ad units?