> For the complete documentation index, see [llms.txt](https://docs.cortex.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cortex.io/ingesting-data-into-cortex/catalogs.md).

# Catalogs overview

A catalog is a defined selection of [entities](/ingesting-data-into-cortex/entities-overview.md). Use catalogs to track and store information about all the components that make up your infrastructure, from services and domains to Amazon Web Services (AWS) resources like S3 buckets and RDS instances, Google Cloud resources, and Azure resources.

Entities are [defined by YAML files](/ingesting-data-into-cortex/entities-overview/entities/yaml.md), but catalogs aren't. You create catalogs in the Cortex UI. Think of a catalog as a folder containing a collection of entities, with each entity defined by its own YAML file. Since an entity can belong to multiple catalogs, you can also think of a catalog as a filter that determines which entities get grouped together.

In the screenshot below, the **Services** page contains a list of all entities that belong to the `service` catalog:

<div align="left" data-with-frame="true"><figure><img src="/files/ULPVbUYjJlW0JUPU0IKi" alt="The services catalog displays a list of services." width="563"><figcaption></figcaption></figure></div>

Watch the video below for an overview of how Cortex helps you build and catalog your engineering operations assets, improving visibility, adoption, and productivity.:

{% embed url="<https://www.youtube.com/watch?v=A5w6ebxGbeg>" %}

{% hint style="success" %}
Want to learn more? Check out the Cortex Academy [course on Catalogs](https://academy.cortex.io/courses/introduction-to-catalogs).
{% endhint %}

## Working with catalogs

By default, Cortex comes with four built-in catalogs:

* **Services** - Contains all [service entities](/ingesting-data-into-cortex/entities-overview/entities/adding-entities/add-services.md).
* **Infrastructure** - Contains all entities representing your infrastructure assets.
  * Cortex pulls in resources directly from [AWS](/ingesting-data-into-cortex/integrations/aws.md), [Azure Resources](/ingesting-data-into-cortex/integrations/azureresources.md), or [Google Cloud](/ingesting-data-into-cortex/integrations/google.md), as their corresponding types out of the box. These resources are automatically added to the Infrastructure catalog.
* **Domains** - Contains all [domain entities](/ingesting-data-into-cortex/entities-overview/entities/adding-entities/domains.md) and their children entities (regardless of entity type), and displays them in a hierarchical view.
* **Teams** - Contains all [team entities](/ingesting-data-into-cortex/entities-overview/entities/adding-entities/teams.md) and displays them in a hierarchical view alongside a leaderboard based on Scorecards.

You can rename these catalogs to fit your own taxonomy. Keep in mind that custom names for default catalogs won't override references to their default names elsewhere in the app. If you want more flexibility, create additional custom catalogs instead.

### Catalog types

Cortex supports two types of catalogs: entity type catalogs and relationship type catalogs.

* **Entity type catalogs** define entity inclusion criteria using filters for entity type, tags, or groups. For example, the built-in **Service** catalog is configured to include entities of type `service`.
* **Relationship type catalogs** group entities based on a specific [entity relationship type](/ingesting-data-into-cortex/entities-overview/entities/defining-relationship-types.md). These catalogs support visualizing hierarchical relationships and let different entity types relate to one another. For example, the built-in **Domain** catalog includes entities connected through a parent/child domain relationship. It displays every entity in the domain hierarchy, including entity types that aren't domains.