Layout > Organizing Entities > Nodes > About Nodes
  
About Nodes
Nodes are branches in the Model Tree. You can use them to simulate actual product organization and to create component hierarchy in a layout. For example, you can organize a layout so that each node represents a different component. An entity in a layout can belong only to one node at a time. Use the shortcut commands in the Model Tree and graphics window to perform operations on nodes.
When working with nodes, keep in mind the following points:
A copied entity remains on the same node as the entity from which it was copied.
You can save and retrieve an entity that belongs to a node to or from a text file. However, the entities and the hierarchy are not retrieved at the same time.
You can toggle the display of nodes on and off.