file_operations struct vs file struct

[Dan Erickson <coldoneknight@rogers.com>]

In chapter 3 of Linux Device Drivers 2nd Edition it says
An open device is identified internally by a file structure, 
and the kernel uses the file_operations structure to access the driver's functions.
	
	My first question would be, when it says " identified internally 
by a file structure", is is refering to *the* file structure, as in 
"struct file", or is it refering to the file_operations structure?

	So basicly if it was refering to the file_operations structure the 
statement would expand to "An open device is identified internally by 
the file_operations structure, and the kernel uses the file_operations structure 
to access the driver's functions."

So which one are they refering to?

 	Also, since I dont seem to understand the basic workings of 
either, could somebody give me a quick overview of both, describing it in 
a diffrent way then LDD did.

	I appolagize for these questions as I didnt know how to word the 
quite properly.

Thanks
-Dan Erickson-
-ColdOneKnight@rogers.com-


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