> ## Documentation Index
> Fetch the complete documentation index at: https://rasa.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Actions

> Responses

## Responses

A [response](/docs/reference/primitives/responses) is a message the assistant will send back to the user. This is
the action you will use most often, when you want the assistant to send text, images, buttons
or similar to the user.

## Custom Actions

A [custom action](/docs/reference/primitives/custom-actions) is an action that can run any code you want. This can be used to make an
API call, or to query a database for example.

## Default Actions

[Default actions](/docs/reference/primitives/default-actions) are actions that are built into the dialogue manager by default. Most of
these are automatically predicted based on certain conversation situations. You may want to
customize these to personalize your assistant.


## Related topics

- [Actions](/docs/reference/integrations/action-server/actions.md)
- [Default Actions](/docs/reference/primitives/default-actions.md)
- [Custom Actions](/docs/reference/primitives/custom-actions.md)
- [Introduction to Actions](/docs/studio/build/actions/introduction.md)