Copies of objects that derive all of their information from the original object. When working with a 3D set one often needs to create duplicates of a single object. This can greatly increase render time, because the computer has to calculate all of the new geometry. Instead of creating a duplicate of an object, one can create an instance. It is important to recognize that one cannot edit an instance’s shape on its own. If the shape is edited, the shape of the original object and all of the instances update to reflect that change.