Asking such a question is taking up the role of leader.
The question seeks to establish a link between the task at hand and how it can be achieved.
It allows one to discriminate between information people would like to have and the one that they need to achieve their task. It doesn’t mean that the territory of knowledge that is going to be defined is restricted by the limit, it defines the area from which to move on in the given situation.
The starting block is knowing what the task is and what it is for.
Asking what needs to be known expands the territory to whatever knowledge is needed to step into the next step.