# Node reference

> Reference for the nodes of a workflow: what the nodes of each category of the Add node panel do, with a link to each category page.

Nodes are the steps of a workflow. To add one, select **+** on the handle of the node it follows, and the **Add node** panel opens. This reference follows the panel's categories and their order. **Search nodes**, at the top of the panel, finds a node by name in every category.

![The Add node panel opened from a Manual trigger, listing the categories Agent, Connector, Data, Document (Preview), Human, Control, Tool, and Wait for event.](https://dev-assets.cms.uipath.com/assets/images/maestro-automate/add-node-categories-automate-db14b6af.webp)

The panel continues with the categories that call existing work.

![The bottom of the Add node panel, listing Maestro Flow, Maestro BPMN, Maestro Case, RPA Workflow, API Workflow, and Function (Preview), after Control, Tool, and Wait for event.](https://dev-assets.cms.uipath.com/assets/images/maestro-automate/add-node-categories-automate-2-2e465275.webp)

| Category | What its nodes do |
|---|---|
| [Agent](agent-nodes.md) | Let AI decide, write, or answer, on its own, in a chat, or on the phone. |
| [Connector](integration-nodes.md) | Call any web address, or act in another app through a connection, such as [Salesforce](connector-salesforce.md), [ServiceNow](connector-servicenow.md), [Slack](connector-slack.md), or [Microsoft Teams](connector-microsoft-teams.md). The page lists every connector. |
| [Data](data-nodes.md) | Reshape lists, apply an instruction to each row of a file, and read or write Data Fabric records. |
| [Document](document-processing.md) (Preview) | Summarize a document, or extract data from it. |
| [Human](human-nodes.md) | Ask a human to approve or fill in a form. |
| [Control](control-nodes.md) | Branch, repeat, merge, and end paths. |
| [Tool](tool-nodes.md) | Run your own code, work with queues, and take part in chats and calls. |
| [Wait for event](wait-for-event-nodes.md) | Pause a run until a time passes or an event arrives. |
| [Call existing work](call-existing-work.md) | Call another workflow, a process, a case, a robot, an API workflow, or a function. |

Every workflow also starts with a trigger, which you choose from the **Change trigger** list instead of this panel. [Triggers](triggers.md) lists them.

## Next steps

- [Your first workflow](your-first-workflow.md): use several of these nodes in one workflow.
- [Guides](guides.md): step-by-step workflows that combine nodes.
- [Community](community.md): ask questions and share workflows with other builders on the UiPath Forum.