| Term | Definition | 
| fabric | a Fibre Channel switch of two or more Fibre Channel switches interconnected to physically | 
| 
 | transmit data between any two N_Ports on the switch or switches | 
| FC | Fibre Channel | 
| F_port | a port in the Fibre Channel fabric where a N_port may attach | 
| FL_port | a port in the Fibre Channel fabric where a NL_port may attach in an arbitrated loop | 
| frame | an indivisible unit for transfer of information in Fibre Channel | 
| frame header | the first field in the frame containing the address and other control information about the frame | 
| a communication protocol which allows transmission in both directions at the same time | |
| half duplex | a communication protocol which allows transmission in both directions, but only one direction at a | 
| 
 | time | 
| host | a processor, usually a CPU and memory, which communicates with devices over an interface | 
| initiator device | a component which originates a command | 
| L_port | a port in an arbitrated loop, either a NL_port or a FL_port | 
| LED | |
| 
 | are used as indicator lights on all sorts of electronic devices | 
| LUN | Logical Unit Number: an identifier for a logical unit  | 
| an optical fiber which can carry several beams of light at once | |
| N_port | a port attached to a node used with point to point or fabric configurations | 
| NL_ port | a port attached to a node in Fibre Channel arbitrated loop or fabric loop configuration | 
| originator | an initiating device; a component which originates a command | 
| parity checking | a method which verifies the accuracy of data transmitted over the SCSI bus by adding one bit in | 
| 
 | the transfer to make the sum of all the bits either odd or even (for odd or even parity); an error | 
| 
 | message occurs if the sum is not correct | 
| PCI | Peripheral Component Interconnect. Allows peripherals to be connected directly to computer | 
| 
 | memory, bypassing the slower ISA and EISA busses | 
| a topology where two ports communicate | |
| port | an access point in a device: see N_port, NL_port, etc. | 
| port address | also port number; the address, assigned by the PCI bus, through which commands are sent to a | 
| 
 | host adapter board | 
| port number | see port address | 
| receiver | the ultimate destination of data transmission; a terminal device | 
| scatter/gather | a device driver feature which allows the host adapter to modify a transfer data pointer so that a | 
| 
 | single host adapter can access many segments of memory, minimizing interrupts and transfer | 
| 
 | overhead | 
| SCSI | Small Computer Systems Interface: a  | 
| 
 | between a computer and intelligent devices including hard disks, floppy disks,  | 
| 
 | scanners, etc. | 
| 
 | an optical fiber with a small core which supports one wavelength (ray of light); the core radius is | 
| 
 | nearly equal to the wavelength of the source | 
| topology | logical layout of the parts of a computer system or network and their interconnections | 
| transceiver | a transmitter/receiver module | 
| transfer rate | the rate at which bytes or bits are transferred, as in megabytes or gigabits per second | 
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