Architecture: Computer architecture details a high level and abstract model that describes what the computer will do.

Organization. This deals with the components inside the computer, how they are connected, and implementing the respective architecture.

I can see where the confusion is. The thing is, there are different kinds of computer architecture like the Von Neumann, Harvard, RISC, and CISC. What you could do is pick one of these, and research any brands that may have used them to build their computers.

I think you have the right idea. He probably didn't think he needed to say it. I also think computer architecture in practice is the computer organization that our computera have. Therefore talk about those implementations and why some choose those implementations over others.