There are some distinct differences between racing spark plugs and regular ones. Racing spark plugs can withstand greater amounts of mechanical shock, in addition to greater amounts of thermal shock (temperature changes). The electrode design in a racing spark plug is constructed to enhance “sparking”. Enhanced sparking means increased combustion reliability. Additionally, the electrodes are made from metals that are more expensive such as, gold/palladium, or platinum. These metals have a lower resistance, and allow more of the power from the ignition system to be delivered to the plugs. This gives a better spark, and more complete combustion.
For more info, see How to Inspect Your Spark Plug Wires (and Why It’s Important)