When you reuse and place a product (and any descendants) somewhere else in the product tree, is the product copied or referenced?
A reference is used. Each product has only one instance in the list of products in the tree. That product can be referenced in one or more locations. If you want a copy, you must create a new product. You can also reuse child products. To reuse child products by creating references, hold the Control key and select the ones you want, and then right-click and select Reuse.