Silver has the highest electrical conductivity of all metallic elements. At room temperature, pure silver carries electric current more efficiently than copper, gold, or aluminium.
Its conductivity comes from silver's metallic bonding and the ease with which conduction electrons move through its crystal lattice. Copper is used much more often in electrical wiring because it is substantially cheaper and abundant enough for large-scale infrastructure. Gold conducts slightly less well than silver, but it resists corrosion and tarnishing, making it valuable for reliable contacts and connectors. Aluminium is lighter and is widely used in overhead transmission lines despite its lower conductivity.
Silver's electrical performance is only one reason it has been prized for thousands of years. Ancient civilizations used it for ornaments, currency, and utensils, while modern technology uses silver in switches, contacts, printed electronics, solar cells, and conductive pastes. Silver can tarnish when sulfur compounds in the environment react with its surface, but that surface film does not change the fact that clean silver has the top conductivity among metals under standard comparison conditions.