Where deals with various geographic and/or logistical aspects of a solution.
These are examples of the kinds of question you should be asking with respect to the “Where” of the intended solution:
Where are the users located?
From where do the users need to be able to use the solution?
From which devices do the users need to be able to interact with the solution?
Where can or should the solution be hosted?
Where will persistent data be stored?
Where will temporary data be stored?
Where will backups be stored?