# Tools

### Definition

The workflow provides a rich selection of tools, categorized into three types:

* **Built-in Tools**: Tools provided by Dify.
* **Custom Tools**: Tools imported or configured via the OpenAPI/Swagger standard format.
* **Workflows**: Workflows that have been published as tools.

Before using built-in tools, you may need to **authorize** the tools.

If built-in tools do not meet your needs, you can create custom tools in the **Dify menu navigation -- Tools** section.

You can also orchestrate a more complex workflow and publish it as a tool.

<figure><img src="/en/.gitbook/assets/guides/workflow/node/tools/image (231).png" alt="" width="258"><figcaption><p>Tool Selection</p></figcaption></figure>

<figure><img src="/en/.gitbook/assets/guides/workflow/node/tools/image (232).png" alt=""><figcaption><p>Configuring Google Search Tool to Retrieve External Knowledge</p></figcaption></figure>

Configuring a tool node generally involves two steps:

1. Authorizing the tool/creating a custom tool/publishing a workflow as a tool.
2. Configuring the tool's input and parameters.

For more information on how to create custom tools and configure them, please refer to the [Tool Configuration Guide](https://docs.dify.ai/v/zh-hans/guides/tools).