This page explains the types of plugins that are installed by default when you
create a Cloud Data Fusion instance. These plugins are available in the
default namespace in your instance, and any new namespaces that you create. You
can download additional plugins from [Hub](https://docs.cloud.google.com/data-fusion/docs/how-to/deploy-a-plugin).

Plugins have the following categories in Cloud Data Fusion. They appear on
the left-hand panel in the Cloud Data Fusion **Studio** page.

## Source

Source plugins connect to databases, files, or real-time streams where your
pipeline reads data. You set up sources for a data pipeline using the web
interface, so you don't have to use code to configure low-level connections.

## Transform

Transformation plugins change data after it's loaded from a source. For
example, you can use these plugins to clone a record, change the file format to
JSON, or create a custom transformation using JavaScript.

## Analytics

Analytics plugins perform aggregations, such as joining data from different
sources and running analytics and machine learning operations.

## Sink

Sink plugins write data to resources, such as Cloud Storage,
BigQuery, Spanner, relational databases, file systems, and
mainframes. You can query the data that gets written to the sink using the
Cloud Data Fusion web interface or REST API.

## Conditions and actions

Condition and action plugins schedule actions that take place during a workflow,
but don't directly manipulate data in the workflow.

Example use cases:

- Schedule a database command to run at the end of your pipeline by adding the Database action plugin to your pipeline.
- Trigger an action that moves files within Cloud Storage by adding the File Move plugin to your pipeline.

## Error handlers and alerts

When stages of the pipeline encounter null values, logical errors, or other
errors, error handler plugins catch them. Use these plugins to find errors in
the output after a transform or analytics plugin in your pipeline. You can write
the errors to a database for analysis.

## What's next

- Learn how to [deploy a plugin from the Cloud Data Fusion Hub](https://docs.cloud.google.com/data-fusion/docs/how-to/deploy-a-plugin).