Cloning an asset creates an identical copy of the asset, owned by whoever has clone it.
It does not clone any of the asset’s dependencies (other assets that are part of the asset). As an example, if you clone a VisComp which has a LightSys, the same LightSys will be shared between the initial VisComp and its clone, meaning that any changes to this LightSys will affect both VisComps.
Cloning is useful for creating copies or new variations of an asset. It also allows the cloner to save changes, so if you need to modify an asset that is owned by someone else, you need to clone it first.