"Stage 1, 2, 3, 8,639" etc.

So growing up in the Fast and Furious hay day, and all the aftermarket manufacturers, I always saw products labeled as "Stage 1 kit", or "Stage 2 kit", which the Stage 2 kit was just the Stage 1 kit with another part(s).

Even Icon still uses this naming convention for their lift kits. Talking with a buddy about motorcycles, he told me his Harley has a "Stage 2" kit that provides more... power. But I don't know what the hell any of the other stages are.

So, am I missing something, and in fact there is a categorical reason to this "Stage X" naming convention. Or is it what I think it is, a marketing thing that a ton of companies do and any "stage" can have any number of parts, but typically more number mean more better?

 

When I was looking for a turbo kit for my Hayabusa, I rechearched a lot and narrowed down to RCC turbos.
Mostly the difference in Stages has to do with how you intend to use your vehicle. I wanted everyday rideability and a stealth look and was recommended the Stage 1 kit. For a more aggressive output and off street use, the Stage 2 was better .
So the Stages correspond to the intended use and how many parts you are willing to swap out from stock.