What's the difference between using ARAnchor to insert a node and directly insert a node?

In ARKit, I have found 2 ways of inserting a node after the hitTest

1. Insert an ARAnchor then create the node in renderer(_ renderer: SCNSceneRenderer, nodeFor anchor: ARAnchor) -> SCNNode?

    let anchor = ARAnchor(transform:hit.worldTransform)
    sceneView.session.add(anchor:anchor)
   

2. Insert the node directly

    node.position = SCNVector3(hit.worldTransform.columns.3.x, hit.worldTransform.columns.3.y, hit.worldTransform.columns.3.z)
    sceneView.scene.rootNode.addChildNode(node)
   

Both look to work for me, but why one way or the other?