> ## Documentation Index
> Fetch the complete documentation index at: https://developers.criteo.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Datasets

A dataset is an entity that encompasses data related to a website or app, captured events through our [OneTag](https://help.criteo.com/kb/en/criteo-onetag-105036), product catalogs, currency, language, and country.

<Info>
  **Dataset is a mandatory requirement when creating a new ad-set through API.**
</Info>

Each advertiser can link to one dataset or more. On the other side, the datasets connect to a single advertiser.