NIS 2011 Firewall Question

I Have Only One (1) Computer, NIS 2011 Firewall asks me if I want to Trust or Restrict Local Network. I was not asked this in NIS 2010. I think I have a LAN connection with my ISP (broadband) cable, or is it Ethernet.. Does it matter?, Thanks,,,Gorpy1 P.S Sorry if this is a dumb question.