# Sub Graph node reference

The Sub Graph node provides a reference to a [Sub Graph](Sub-graph.md). Use Sub Graphs to share functionality between shader graphs, or duplicate the same functionality within a graph.

The inputs and outputs of a Sub Graph node are defined by the properties and outputs of the Sub Graph. For more information, refer to [Create a Sub Graph](Create-Sub-Graph.md).

The preview in the Sub Graph node displays the first output of the Sub Graph.

Some built-in nodes are Sub Graph nodes, for example the [ThreadMapDetail node](ThreadMapDetail-Node.md) and the [SpeedTree](SpeedTree8-SubGraphAssets.md) nodes.

## Additional resources

- [Sub Graphs](Sub-graph.md)