Nodes in a 3D modeling viewport are visual, connectable blocks representing components (e.g., materials, modifiers, data) that build and control a scene’s properties—you see their effects live.
They’re modular: Linking them in a node graph lets you flexibly adjust a model’s appearance (mixing textures) or behavior (deforming meshes) without coding.
For beginners, start with basic material nodes (combining base color + roughness) to experiment with connections and see instant viewport results.