OK ill make it simple

Iridium Specifications:

Designed specifically for the performance enthusiast. Iridium Plugs offer extreme ignitability, improved throttle response and superior anti fouling

* Fine Iridium tip ensures high durability and a consistently stable spark
* Iridium alloy has extremely high melting point, perfect for today's high-tech, high-performance engines
* Outstanding acceleration, high fuel efficiency and durability
* Ultimate design, technology and performance.

Plain and simple it lasts longer runs better and improves fuel efficiency.

I run the Iridium spark plug in my engine and I see a significant difference and improvement.