Copper cables are the oldest installed cables and it is still the most used material for connecting devices, almost every topology has its copper version. Copper is a very good electrical conductor this means that the resistance of a length of copper cable is relatively low. An aluminum cable would have nearly twice the resistance of a copper cable with the same dimensions therefore the energy losses in the aluminum cable will be higher than in the copper cable. The copper cable is more energy efficient. The copper cable has several advantages over the aluminum because it is thinner; it can fit into smaller duct spaces; it can be bent around tighter corners and also copper can be easily jointed. Copper is three times as dense as aluminum.