A 12-gauge wire is a type of electrical wire commonly used in residential and commercial wiring. The "gauge" refers to the wire's thickness, with lower numbers indicating thicker wires. A 12-gauge wire is suitable for carrying higher electrical loads, making it ideal for circuits that power appliances like water heaters and air conditioners. This wire is typically made of copper or aluminum and is insulated to prevent electrical shocks. It is often used in branch circuits and can handle up to 20 amps of current. Proper use of 12-gauge wire ensures safety and efficiency in electrical systems.