[Cluster nodes](/glossary.md#cluster-node-n8n) are node groups that work together to provide functionality in an n8n workflow. Instead of using a single node, you use a [root node](/glossary.md#root-node-n8n) and one or more [sub-nodes](/glossary.md#sub-node-n8n) that extend the functionality of the node.

![Screenshot of a workflow with a root node and two sub-nodes](/_images/integrations/builtin/cluster-nodes/root-sub-nodes.png)
