to whom "logoff event" send?

If a user logged off from Windows Server 2003 (or the other Windows OS),

to which (area, i mean session?,applications?,etc) is the "logoff event"

sent?

I first thought it might send to the processes that the user executed.

But, a process which was created by a windows service recived the logoff

event.

I want to know the exact range to which the "logoff event" send.

If you have any infomation, please let me know.

like the web page, or book recommendation will be very helpful too.

Thank you.