UnityCACAO-HDRP17/com.unity.render-pipelines.high-definition/Documentation~/render-graph.md

Customize the the High Definition Render Pipeline (HDRP)

The High Definition Render Pipeline (HDRP) uses the render graph system in its implementation. This means that if you want to extend HDRP and implement your own render pipeline features, you need to learn how the render graph system works and how to write rendering code using it. For information on the render graph system and how to use it to write render pipeline features, see the render graph system documentation.