Let's assume a category landing page (clothing > dresses) is rendered. The client requests the Campaigns Delivery API with the channel type "category-page" and the refinements "clothing" and "dresses". The only campaign that defines content for this page is the "summer-collection dresses" campaign, because it is valid for every category page with refinement summer or clothing. The Delivery API will return the content UUIDs of the CoreMedia content that was assigned to the "hero" slot in the Campaign App for the Campaign "summer-collection dresses". Of course this only happens within the configured start and end date for the campaign and only if the campaign was set active.