The days when you changed your spark plugs every couple years has ended. Spark plugs are designed better and made of better materials that last longer. Modern engine-management controls also help reduce spark plug damage from excess carbon deposits. Engine control computers precisely regulate the time when fuel is injected into the engine and when spark plugs fire.
Electricity from the battery goes into a coil that allows power to build up to anywhere from 12,000 to 45,000 volts, depending on the vehicle. The engine management computer tells the coil when to release the power to the spark plug. The electricity travels through a wire from the coil to the spark plug. At the tip of the plug, a spark jumps between two electrodes and ignites the gas in the combustion chamber.
Some engines have more than one coil. Coils wear out and need to be replaced. The spark plug wires can also wear out and need replacement.
Because engines are designed to run with different internal temperatures, spark plugs have different designs to work properly within those temperatures. Your service advisor here will be able to get the right plugs for your vehicle and advise you on when you should replace your spark plugs.