Some GIS doubts

Hi everybody,

I have some doubts on GIS and I hope you can help me clarify them:

-What is the difference between position, place and location (if any)?
I think these terms have some subtle difference between them.

-What are concept/spatial hierarchies used for? I think the typical use
is to store spatial relatioships between spatial objects (e.g., a
country is part of a state and overlaps with another one), so this is
used for spatial reasoning, but I want to make sure that my perception
is right. What's the concept of context in GIS?

-What's the role of ontologies in GIS? Again, I think ontologies are
proposed to replace the spatial hierarchies because they provide a
common vocabulary to reason.

I'd ve grateful if you can point me to the answers to these questions.
Literature on GIS is abundant and I cannot find the right sources.

Thanks in advance,

S.