Sorry if it's a basic question, but I'm nearly a newbie about this ...

I think Blackberry always stays connected to the device and is able to
"push" the emails (for example) as it knows where to send them (IP
address I think).

What about the GWMS? Is it more a "pull & push" functionnaliy as there
got to install a client on the devices?

I didn't find anyhthing very clear on the documentation (or maybe it's
just because my English is too poor!!), is there some document I can
find about this, or somebody maybe can give some details on how it works?