Inventory in Google Ad Manager is the ad space on your website or app where you display ads. Inventory is what you sell to advertisers or buyers. Ad space in Ad Manager is represented by ad units. You can also use placements to group ad units together.
When you create ad units, you also generate code. This code is then inserted on pages of your website or parts of your app. When a user visits your website or app, the code makes a request for an ad from Ad Manager. If there's an eligible ad campaign in your Ad Manager network, an ad is then shown on your website or app.
How people talk about "inventory"
The term inventory is often used more broadly by other Ad Manager users or across the digital ads industry. Often, inventory includes not just the space on your website or app but also targeting.
- Where: Targeting allows you to limit where an ad shows on your website or app. Advertisers, for example, might only want to show ads on your homepage and not the rest of your website.
One important feature you'll encounter when thinking about where ads show is key-values. Key-values are versatile and are used in many ways in Ad Manager. One important way is to define where particular ad space lives on your website or app. Learn more in Structure your inventory.
- Who: Targeting can limit to whom an ad shows. Advertisers might find it more valuable, for instance, to reach users on your website or app who are in New York City and between the ages of 18 and 32.
When you sell inventory, then, you're not just selling the ad space on your digital property, but you're also selling the targeting—to whom or where an ad can appear.
Targeting is an important and robust feature of Google Ad Manager. You can start to learn more about it in About targeting.
You can define your networks' inventory structure in the Inventory section of your Ad Manager network.