The clone operation creates an independent deep (on client, and if applicable on server) copy of either a model or a created part including all of its attributes. A cloned model part is a reloaded model part with its attributes updated to match the original.
Note: A cloned model part has no parent as it remains an independent model part. A cloned created part recreates the created part with all of the attributes updated to match the original. Note: a cloned created part retains the same parentage as the original. Remember that a cloned part uses the same amount of memory on both the client and server as the original part.
A cloned part will recreate a new part identical to the selected part. The cloned part will inherit all of the model variables available to it as a model part or from the parents if the clone is a created part. The clone will not, however, inherit calculated variables from the part that is being cloned. If you wish to have calculated variables extended to include the cloned part you must recalculate these variables.
In contrast, a part copy (see Copy Parts) is a shallow operation, existing only on the client (visual only). Shallow copying of a part is useful to save memory on the server, and is best used if all that is needed is to color the part by two different variables, perhaps in two different viewports. A shallow copy is cheaper in terms of memory usage but limited to visual operations only.