Socket - typically tells you the kind of processor it supports.
It has a certain number of pins.
That is why you can never upgrade a motherboard/processor alone,
due to the sockets.
If you choose to upgrade individually, you have to do a lot of
research.
Go to the motherboard manufacturer's website and check out what
type of processors is supported or what type of socket is supported
by a particular motherboard model.
Another website to go is http://www.motherboards.org/.
You select the type of socket and it will give you a list of
motherboard using that socket and vice versa.
Socket F is just another type of socket supporting certain
processors, specifically, the AMD Opteron processors.