lspci show the info about your PCI devices (depending on options), you can check the man page for futher info.
Regarding the REGION header on the output, these lines details where is allocated the registers used for this component. It is related with the memory mapping and how the memory is used for each component.
Region 0: Memory at f7a00000 (64-bit, non-prefetchable) [size=2M]
Region 2: Memory at f79ff000 (64-bit, non-prefetchable)
On these lines are specified the register addresses used, the size and the address size (64 bits to point a register).
Look for futher info about computer architecture if you want to go deeper on the way this addresses are used.
Hope it helps!
