# Collections

A collection in Umbraco Compose is a container for logically grouping related content. There may be one or more collections per [environment](https://docs.umbraco.com/umbraco-compose/content-orchestration/environments). The content instances you ingest should be placed into an existing collection of your choice.

## Collection Considerations

When designing your content architecture in Umbraco Compose, you should keep in mind some collection principles.

Requests to the GraphQL API will always target a single collection for the root content that they return. However, it is also possible to retrieve other content in a single query if it is [referenced](https://docs.umbraco.com/umbraco-compose/content-orchestration/referenced-content) from an item in the target collection.

GraphQL queries will return all items in the target collection unless they are explicitly [filtered out](https://docs.umbraco.com/umbraco-compose/apis/graphql/filtering).