---
id: viewing-catalog
title: Viewing the Catalog
sidebar_label: Viewing the Catalog
description: Viewing the Catalog
---

Audience: All

## Overview

Initially, when you log into your standalone Backstage App, `Home` is selected in the sidebar, which displays the Catalog in the main panel.

There are four main entities that you should become familiar with:

- `Components` - Individual pieces of software that can be tracked in source control and can implement APIs for other components to consume.
- `Resources` - The physical or virtual infrastructure needed to operate a component.
- `Systems` - A collection of resources and components that cooperate to perform a function by exposing one or several public APIs. It hides the resources and private APIs between the components from the consumer.
- `Domains` - A collection of systems that share terminology, domain models, metrics, KPIs, business purpose, or documentation.

The [Technical Overview](../overview/technical-overview.md#software-catalog-system-model) provides a description of all of the types of entities displayed in the Catalog.

It should be noted that you can also [create your own kinds of entities](../features/software-catalog/extending-the-model.md#adding-a-new-kind), if you need to model something in your organization that does not map to one of the existing entity types.

Initially, the Catalog displays registered entities matching the following filter settings:

- `Kind` - Component
- `Type` - all
- `Owner` - Owned
- `Lifecycle` - list of [lifecycle](../features/software-catalog/descriptor-format.md#speclifecycle-required) values of entities in the Catalog
- `Processing Status` - normal
- `Namespace` - The ID of a [namespace](../features/software-catalog/descriptor-format.md#namespace-optional) to which the entity belongs

You can change the initial setting for the [Owner](../features/software-catalog/catalog-customization.md#catalog-filters) and [Kind](../features/software-catalog/catalog-customization.md#catalog-filters) filters.

## Informational columns for each entity

For each kind of entity, a set of columns display information regarding the entity. For example, the default set of information for a `Component` is:

- `Name` - the name of the component
- `System` - an optional field that references the system to which the component belongs
- `Owner` - the owner of the component
- `Type` - common types are as follows, but you can [create a new type](../features/software-catalog/extending-the-model.md#adding-a-new-type-of-an-existing-kind) to meet your organization's needs
  - `service` - a backend service, typically exposing an API
  - `website` - a website
  - `library` - a software library, such as an npm module or a Java library
- `Lifecycle`
  - `experimental` - an experiment or early, non-production component, signaling
    that users may not prefer to consume it over other more established
    components, or that there are low or no reliability guarantees
  - `production` - an established, owned, maintained component
  - `deprecated` - a component that is at the end of its lifecycle, and may
    disappear at a later point in time
- `Description` - an optional field that describes the component.
- `Tags` - an optional field that can be used for searching
- `Actions` - see [Catalog Actions](#catalog-actions)

You can modify the columns associated with each kind of entity, following the instructions in [Customizing columns, actions, and table options](../features/software-catalog/catalog-customization.md#customizing-columns-actions-and-table-options).

## Catalog Actions

For each entity, there are a set of actions that are available.

![Screenshot explaining entity actions.](../assets/uiguide/entity-actions.png)

From left to right, the actions are:

- View - View the `catalog-info.yaml` file that defines the entity.
- Edit - Edit the `catalog-info.yaml` file that defines the entity. See [Updating a Component](../getting-started/update-a-component.md)
- Star - Designate the entity as a favorite. You can [filter](../getting-started/filter-catalog.md) the catalog for starred entities.

[Customizing columns, actions, and table options](../features/software-catalog/catalog-customization.md#customizing-columns-actions-and-table-options) describes how you can modify the actions that are displayed.

## Viewing entity details

Selecting an entity in the main panel displays details of the entity. The type of details depends on the type of entity. For example, selecting a Component, such as `example-website`, displays the following details:

- `About` - Metadata for the entity, such as description, owner, tags, and domain.
- `Relations` - see [Viewing entity relationships](../getting-started/viewing-entity-relationships.md)
- `Links` - any links associated with the entity
- `Has subcomponents` - An entity reference to another component of which the component is a part

Selecting a System, such as `examples`, displays `About`, `Relations`, and `Links` similar to a Component, but it also includes `Has components`, `APIs` and `Has Resources`.

![Details of system entity.](../assets/uiguide/details-system-entity.png)