Dell PowerEdge SC1420 - Manual (Page 23)

directory — Directories help keep related files organized on a disk in a hierarchical, "inverted tree" structure. Each disk has a "root" directory. Additional
directories that branch off the root directory are called subdirectories. Subdirectories may contain additional directories branching off them.
DMA — Direct memory access. A DMA channel allows certain types of data transfer between RAM and a device to bypass the processor.
DMI — Desktop Management Interface. DMI enables the management of your system's software and hardware by collecting information about the system's
components, such as the operating system, memory, peripherals, expansion cards, and asset tag.
DNS — Domain Name System. A method of translating Internet domain names, such as www.dell.com, into IP addresses, such as 143.166.83.200.
DRAM — Dynamic random-access memory. A system's RAM is usually made up entirely of DRAM chips.
DVD — Digital versatile disc.
ECC — Error checking and correction.
ECP — Extended capabilities port. A parallel connector design that provides improved bidirectional data transmission. Similar to EPP, it uses direct memory
access to transfer data and often improves performance.
EEPROM — Electronically erasable programmable read-only memory.
EMC — Electromagnetic compatibility.
EMI — Electromagnetic interference.
ERA — Embedded remote access. ERA allows you to perform remote, or "out-of-band," server management on your network server using a remote access
controller.
ESD — Electrostatic discharge.
ESM — Embedded server management.
expansion bus — Your system contains an expansion bus that allows the processor to communicate with controllers for peripherals, such as NICs.
expansion card — An add-in card, such as a NIC or SCSI adapter, that plugs into an expansion-card connector on the system board. An expansion card adds
some specialized function to the system by providing an interface between the expansion bus and a peripheral.
expansion-card connector — A connector on the system board or riser board for plugging in an expansion card.
F — Fahrenheit.
FAT — File allocation table. The file system structure used by MS-DOS to organize and keep track of file storage. The Microsoft® Windows® operating
systems can optionally use a FAT file system structure.
flash memory — A type of EEPROM chip that can be reprogrammed from a utility on diskette while still installed in a system; most EEPROM chips can only be
rewritten with special programming equipment.
format — To prepare a hard drive or diskette for storing files. An unconditional format deletes all data stored on the disk.
FSB — Front-side bus. The FSB is the data path and physical interface between the processor and the main memory (RAM).
ft — Feet.
FTP — File transfer protocol.
g — Gram(s).
G — Gravities.
Gb — Gigabit(s); 1024 megabits or 1,073,741,824 bits.
GB — Gigabyte(s); 1024 megabytes or 1,073,741,824 bytes. However, when referring to hard-drive capacity, the term is usually rounded to 1,000,000,000
bytes.
graphics mode — A video mode that can be defined as x horizontal by y vertical pixels by z colors.
group — As it relates to DMI, a group is a data structure that defines common information, or attributes, about a manageable component.
guarding — A type of data redundancy in which a set of physical drives stores data and an additional drive stores parity data. See also mirroring, striping,
and RAID.
h — Hexadecimal. A base-16 numbering system, often used in programming to identify addresses in the system's RAM and I/O memory addresses for
devices. In text, hexadecimal numbers are often followed by h.
headless system — A system or device that functions without having a keyboard, mouse, or monitor attached. Normally, headless systems are managed
over a network using an Internet browser.
host adapter — A host adapter implements communication between the system's bus and the controller for a peripheral device. (Hard-drive controller
subsystems include integrated host adapter circuitry.) To add a SCSI expansion bus to your system, you must install or connect the appropriate host
adapter.
Hz — Hertz.
I/O — Input/output. A keyboard is an input device, and a monitor is an output device. In general, I/O activity can be differentiated from computational
activity.
ID — Identification.
IDE — Integrated drive electronics. A standard interface between the system board and storage devices.
integrated mirroring — Provides simultaneous physical mirroring of two drives. Integrated mirroring functionality is provided by the system's hardware. See
also mirroring.
internal processor cache — An instruction and data cache built into the processor.
IP — Internet Protocol.
IPX — Internet package exchange.
IRQ — Interrupt request. A signal that data is about to be sent to or received by a peripheral device travels by an IRQ line to the processor. Each peripheral
connection must be assigned an IRQ number. Two devices can share the same IRQ assignment, but you cannot operate both devices simultaneously.
jumper — Small blocks on a circuit board with two or more pins emerging from them. Plastic plugs containing a wire fit down over the pins. The wire connects
the pins and creates a circuit, providing a simple and reversible method of changing the circuitry in a board.
K — Kilo-; 1000.
Kb — Kilobit(s); 1024 bits.
KB — Kilobyte(s); 1024 bytes.
Kbps — Kilobit(s) per second.
KBps — Kilobyte(s) per second.