There are three protocols used with Fibre Channel networking:
Point-to-Point protocol is used when connecting storage directly to the host. Only two devices are involved.
Arbitrated loop protocol works as a "party line" for all of the entities on the network. Regardless of the number of connected devices, only two devices can communicate at any one moment. An 8-bit addressing system is used to route data from one entity to another.
Fabric switches are similar to Ethernet switches, in that multiple communications can be occurring on the switchas many as are needed at any given moment. A 24-bit addressing system is used to route data from one entity to another.