Whose usually relates to a person, but it can relate to other things, especially a
country or organization.
I wouldn't fly with an airline whose safety record is so poor.
(Its safety record is so poor.)
The others were playing a game whose rules I couldn't understand.
NOTE
Instead of whose relating to a thing, we can use this pattern with of which.
The others were playing a game the rules of which I couldn't understand.
We are introducing a new system, the aim of which is to reduce costs