# The inventory's structure

A **publisher** distributes content through one or more media platforms. Online advertising is often the business model of choice to benefit financially from these platforms. A publisher reserves a certain amount of space for advertising purposes: the **inventory***.* A publisher is free to choose how it organises and structures its inventory. Adhese supports the client as a strategic partner during this phase of the implementation process.

Each piece of a publisher’s inventory is a **position**. A position is a combination of a **location** (i.e. a section within a publication) and a **format**. The following diagram is a simplified representation of an inventory’s structure.

[![the_inventorys_structure_positions1.png](https://documentation.adhese.org/uploads/images/gallery/2024-06/scaled-1680-/HpFV1SzWZTrBbJBk-the-inventorys-structure-positions1.png)](https://documentation.adhese.org/uploads/images/gallery/2024-06/HpFV1SzWZTrBbJBk-the-inventorys-structure-positions1.png)

See [Positions](https://documentation.adhese.org/books/inventory-setup/page/positions) for a diagram that includes concrete examples of publishers, publications, locations and formats.

### The structure of a position

#### Publication

A publisher maintains online **publications** such as a website, blog, video channel, newsletter, smartphone app, or webshop. Adhese is platform-agnostic and able to support all online publications.

#### Location

A **location** is a (sub)section within a publication, for example, the home page.

#### Format

A **format** defines the conditions, such as the file size and dimensions, that a creative must meet to avoid errors while uploading the creative file. A format is not limited to online banner ads. It can also be a native ad or a video ad.

There are two types of formats: **main** and **sub formats**. The ad tag for the main format can also fetch the defined sub-formats of its main format. Sub formats appear in the same position as their main format. However, sub formats can have different dimensions. [Create a format](https://documentation.adhese.org/books/inventory-setup/page/formats) elaborates on how to distinguish between main and sub formats.

Refer to the Appendix [Online advertising formats](https://documentation.adhese.org/books/integrations-and-delivery/page/online-advertising-formats) to define the most important formats and their representation within their environment. The overview is not exhaustive. A publisher can also implement custom formats.

### Channels

[Channels](https://documentation.adhese.org/books/inventory-management/page/channels) are a collection of positions within a publication (e.g. run-of-site) or across your network of publications (e.g. run-of-network). **Channels** group identical formats across different locations, making it easy to target ads on similar web pages.