[albedoa]

> I normally have an idea, but not in this context, as it speaks of stages of a product definition. A definition does not have “stages”

It's really difficult to understand your confusion here. "Definition" is referring the the act of defining, not the formal statement that results from that process. Are you reading it as the latter?

Every product I have ever worked on had definition stages. How else does the formal definition come into being?