about the information architecture

After reading material about the information architecture, I think I gain its basic concept. I am trying to explain my understanding in this way. It is just like the way you take the MTR and attempt to find exit. The process of reaching your destination will be the job of information architecture. It is not taken for granted or by luck that you could find your route subsequently. But rather it is because of your past experience (ie. walk according to the instruction indicator)that directs you to the MTR exit. All in all, this past experience is so-called usability - the ability for users to figure out some information by common sense. And information architecture is how you present the exit indicator into the most readable way that leads the passengers to their way. I hope this example can somehow give you an idea of what information arhitecture is.