An FC adapter, which uses the Peripheral Component Interconnect (PCI) slots on the server, can have one, two or four ports. The number of adapters used in an implementation depends on the use case -- for example, storage features such as redundancy or the need for a faster connection might require additional ports. Most adapters are backward-compatible with previous generation connection speeds.
Some adapter vendors provide their own management software, although most adaptors are recognized by existing SAN management software.
See also: host bus adapter (HBA)