Glossary of computer hardware terms

This glossary of computer hardware terms is a list of definitions of terms and concepts related to computer hardware, i.e. the physical and structural components of computers, architectural issues, and peripheral devices.

A

Accelerated Graphics Port (AGP): A dedicated video bus standard introduced by INTEL enabling 3D graphics capabilities; commonly present on an AGP slot on the motherboard. (Presently a historical expansion card standard, designed for attaching a video card to a computer's motherboard (and considered high-speed at launch, one of the last off-chip parallel communication standards), primarily to assist in the acceleration of 3D computer graphics). Has largely been replaced by PCI Express since the mid 2000s.
accelerator: A microprocessor, ASIC, or expansion card designed to offload a specific task from the CPU, often containing fixed-function hardware. A common example is a graphics processing unit.
accumulator: A register that holds the result of previous operation in ALU. It can be also used as an input register to the adder.
address: The unique integer number that identifies a memory location or an input/output port in an address space.
address space: A mapping of logical
physical memory or other memory-mapped devices
.
Advanced Technology eXtended (ATX): A motherboard form factor specification developed by Intel in 1995 to improve on previous DE factor standards like the AT form factor.
AI accelerator: An
tensor processing unit
, etc.
Advanced Configuration and Power Interface: An open standard for operating systems to discover, configure, manage, and monitor status of the hardware.

B

Blu-ray Disc (BD): An optical disc storage medium designed to supersede the DVD format. Blu-ray Disc is capable of storing about 5 times as much data as a standard DVD. Most computers do not come shipped with Blu-ray drives, however they can be purchased and added as a separate upgrade. Blu-ray won a format war against HD DVD and for a time drives offering both formats were sold.
bus: A common path shared by multiple subsystems or components to send / receive signals. It is a low cost option in mini and micro computers compared to multiple dedicated non- shared paths in main frame computers.
Bottleneck: An occurrence where a certain component compromises the way another component works.

C

cache: A small and fast buffer memory between CPU and Main memory. Reduces access time for frequently accessed items (instructions / operands).
cache coherency: The process of keeping data in multiple caches synchronised in a multiprocessor shared memory system, also required when DMA modifies the underlying memory.
cache eviction: Freeing up data from within a
cache replacement policy. Caused by a cache miss
whilst a cache is already full.
cache hit: Finding
data in a local cache
, preventing the need to search for that resource in a more distant location (or to repeat a calculation).
cache line: A small block of memory within a cache; the granularity of allocation, refills, eviction; typically 32–128 bytes in size.
cache miss: Not finding
evicting
other data to make room.
cache thrashing: A pathological situation where access in a
evicting
data that is needed in the near future.
cache ways: The number of potential
associative cache that specific physical addresses
can be mapped to; higher values reduce potential collisions in allocation.
cache-only memory architecture (COMA): A multiprocessor memory architecture where an address space is dynamically shifted between processor nodes based on demand.
card reader: Any data input device that reads data from a card-shaped storage medium such as a memory card.^[1]^[2]^[3]
channel I/O: A generic term that refers to a high-performance input/output (I/O) architecture that is implemented in various forms on a number of computer architectures, especially on mainframe computers.
chipset: A group of integrated circuits, or chips, that are designed to work together. They are usually marketed as a single product.
Compact Disc-Recordable (CD-R): A variation of the optical compact disc which can be written to once.
Compact Disc-ReWritable (CD-RW): A variation of the optical compact disc which can be written to many times.
Compact Disc Read-Only Memory (CD-ROM): A pre-pressed compact disc which contains data or music playback and which cannot be written to.
computer case: The enclosure that contains most of the components of a computer, usually excluding the display, keyboard, mouse, and various other peripherals.
computer fan: An active cooling system forcing airflow inside or around a computer case using a fan to cause air cooling.
computer form factor: The name used to denote the dimensions, power supply type, location of mounting holes, number of ports on the back panel, etc.
control store: The memory that stores the microcode of a CPU.
Conventional Peripheral Component Interconnect (Conventional PCI): A computer bus for attaching hardware devices in a computer.
core: The portion of the
logical operations
; nearly all CPUs produced since the late 2000s decade have multiple cores (e.g. "a quad-core processor").
core memory: In modern usage, a synonym for
magnetic core memory
.
Central Processing Unit (CPU): The portion of a computer system that executes the instructions of a computer program.

D

data cache (D-cache): A
load and store requests, mirroring main memory (or VRAM for a GPU
).
data storage: A technology consisting of computer components and
data. It is a core function and fundamental component of computers.^[1]
device memory: compute device, distinct from main memory
.
Digital Video Disc (DVD): An optical compact disc - of the same dimensions as compact discs (CDs), but store more than six times as much data. Primarily used for storing movies and computer games, however, the rise of services such as Steam have largely rendered physical game discs obsolete.
Digital Visual Interface (DVI): A video display interface developed by the Digital Display Working Group (DDWG). The digital interface is used to connect a video source to a display device, such as a computer monitor.
Direct Access Storage Device (DASD): A mainframe terminology introduced by IBM denoting secondary storage with random access, typically (arrays of) hard disk drives.
direct mapped cache: A cache where each physical address may only be mapped to one cache line, indexed using the low bits of the address. Simple but highly prone to allocation conflicts.
direct memory access (DMA): The ability of a
DMA channels
in a system.
DisplayPort: A digital display interface developed by the Video Electronics Standards Association (VESA). The interface is primarily used to connect a video source to a display device such as a computer monitor, though it can also be used to transmit audio, USB, and other forms of data. Unline HDMI, DisplayPort is open source.
drive bay: A standard-sized area within a computer case for adding hardware (hard drives, CD drives, etc.) to a computer.
dual in-line memory module (DIMM): A series of dynamic random-access memory integrated circuits. These modules are mounted on a printed circuit board and designed for use in personal computers, workstations and servers. Contrast SIMM.
dual issue: A
superscalar
pipeline capable of executing two instructions simultaneously.
dynamic random-access memory (DRAM): A type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit and which must be periodically refreshed to retain the stored data.

E

expansion bus: A
protocols
that allows for the expansion of a computer.
expansion card: A printed circuit board that can be inserted into an electrical connector or expansion slot on a computer motherboard, backplane, or riser card to add functionality to a computer system via an expansion bus.

F

firewall: Any hardware device or software program designed to protect a computer from viruses, trojans, malware, etc.
firmware: Fixed programs and data that internally control various electronic devices.
flash memory: A type of non-volatile computer storage chip that can be electrically erased and reprogrammed.
floppy disk: A data storage medium that is composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell. Historically floppy disks came in 8-inch, 5.25-inch, and 3.5-inch sizes, with the latter being by far the most ubiquitous.
floppy disk drive: A device for reading floppy disks. These were common on computers made prior to 2010.
floppy-disk controller: A specific area on the motherboard which can be used to connect a floppy disk drive to it.
free and open-source graphics device driver

G

graphics hardware
Graphics Processing Unit (GPU): A specialized processor designed for the purpose of creating images and animations and displaying them on a computer screen, independent of the CPU and onboard video memory.

H

hard disk drive (HDD): Any non-volatile storage device that stores data on rapidly rotating rigid (i.e. hard) platters with magnetic surfaces.
hardware: The physical components of a computer system.
Harvard architecture: A
program machine code and data are held in separate memories, more commonly seen in microcontrollers and digital signal processors
.
High-Definition Multimedia Interface (HDMI): A compact interface for transferring encrypted uncompressed digital audio and video data to a device such as a computer monitor, video projector or digital television. Motherboard and graphics card manufacturers must pay a licensing fee to incorporate HDMI into their products.

I

input device: Any peripheral equipment used to provide data and control signals to an information processing system.
input/output (I/O): The communication between an information processing system (such as a computer), and the outside world.
Input/Output Operations Per Second (IOPS): A common performance measurement used to benchmark
computer storage devices like hard disk drives
.
instruction: A group of several bits in a computer program that contains an operation code and usually one or more memory addresses.
instruction cache
I-cache: A
physical memory
as data.
instruction fetch: A stage in a pipeline that loads the next instruction referred to by the program counter.
integrated circuit: A miniaturised electronic circuit that has been manufactured in the surface of a thin substrate of semiconductor material.
interrupt: A condition related to the state of the hardware that may be signaled by an external hardware device.

J

jump drive: Another name for a USB flash drive.

K

keyboard: An
keys to act as mechanical levers or electronic switches
.

L

load/store instructions

M

magneto-optical drive
mainframe computer: An especially powerful computer used mainly by large organizations for bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.
main memory: The largest random-access memory in a memory hierarchy (before offline storage) in a computer system. Main memory usually consists of DRAM, and is distinct from caches and scratchpads.
mask ROM: A type of read-only memory (ROM) whose contents are programmed by the integrated circuit manufacturer.
memory: Devices that are used to store data or programs on a temporary or permanent basis for use in an electronic digital computer.
memory access pattern: The pattern with which software or some other system (such as an accelerator or DMA channel) accesses, reads, and writes memory on secondary storage. These patterns have implications for locality of reference, parallelism, and the distribution of workload in shared memory systems.
memory address: The address of a location in a memory or other address space.
memory architecture: A memory architecture in a
computer system, e.g. NUMA, uniform memory access, COMA
, etc.
memory card: A small electronic data storage device consisting of a flat piece of plastic no larger than a thumbnail that can be inserted into a special socket in a computer or a portable electronic device such as a camera or a cell phone in order to provide instant access to removable memory, typically flash memory.
mini-VGA: Small connectors used on some laptops and other systems in place of the standard VGA connector.
microcode: A layer of hardware-level instructions involved in the implementation of higher level machine code instructions in many computers and other processors.
modem: A device that enables two distant computer systems to communicate with one another. In the past, modems connected to a phone line, however, since the mid 2000s broadband modems have been the predominant type seen.
modified Harvard architecture: A variation of Harvard architecture used for most CPUs with separate non-coherent instruction and data caches (assuming that code is immutable), but still mirroring the same main memory address space, and possibly sharing higher levels of the same cache hierarchy.
monitor: An
cathode ray tube (CRT).^[1]
motherboard: The central printed circuit board (PCB) in many modern computers which provides a physical platform for attaching and arranging many of the crucial components of the system, usually while also providing connection space for peripherals.^[5]
mouse: A
screen space; typically used to control a graphical user interface on a desktop computer or for CAD
, etc.

N

network: A collection of computers and other devices connected by communications channels, e.g. by Ethernet or wireless networking.
network interface controller: ^[6]
network on a chip (NOC): A
semiconductor chip, connecting processing elements, fixed-function hardware, or even memories and caches. Increasingly common in system on a chip
designs.
non-uniform memory access (NUMA)
non-volatile memory: memory that can retain the stored data even when not powered, as opposed to volatile memory.
non-volatile random-access memory: Random-access memory (RAM) that retains its data when power is turned off.

O

operating system: The set of software that manages computer hardware resources and provides common services for computer programs, typically loaded by the BIOS on booting.
operation code: Several bits in a computer program instruction that specify which operation to perform.
optical disc drive: A type of
light spectrum as part of the process of reading or writing data to or from optical discs
.

P

pen drive

R

Redundant Array of Independent Disks (RAID): Any of various data storage schemes that can divide and replicate data across multiple hard disk drives in order to increase reliability, allow faster access, or both.
random-access memory (RAM): A type of computer data storage that allows data items to be accessed (
demultiplexing circuitry to connect the data lines to the addressed storage for reading or writing the entry. Usually, more than one bit of storage is accessed by the same address, and RAM devices often have multiple data lines and are said to be '8-bit' or '16-bit' etc. devices. In today's technology, random-access memory takes the form of integrated circuits
.
read-only memory (ROM): A type of memory chip that retains its data when its power supply is switched off.

S

server: A computer which may be used to provide services to clients.
software: Any computer program or other kind of information that can be read and/or written by a computer.
single in-line memory module (SIMM): A type of memory module containing random-access memory used in computers from the early 1980s to the late 1990s. Contrast DIMM.
solid-state drive: Any data storage device that uses integrated circuit assemblies as memory to store data persistently. Though they are sometimes referred to as solid-state disks, these devices contain neither an actual disk nor a drive motor to spin a disk. On average, solid-state drives cost about four times as much as conventional hard drives of the same capacity, but can provide significantly faster boot times.
static random-access memory (SRAM): A type of semiconductor memory that uses bistable latching circuitry to store each bit. The term static differentiates it from DRAM, which must be periodically refreshed.
sound card: An internal expansion card that facilitates economical input and output of audio signals to and from a computer under control of computer programs.
storage device
synchronous dynamic random-access memory (SDRAM): A type of dynamic random access memory that is synchronized with the system bus.
SuperDisk: A high-speed, high-capacity alternative to the 90 mm (3.5 in), 1.44
Imation
in 1997.
Serial ATA (SATA): A computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives.

T

tape drive: A peripheral storage device that allows only sequential access, typically using magnetic tape.
task manager
terminal: An
electromechanical
hardware device that is used for entering data into, and displaying data from, a computer or a computing system.
touchpad: A
fingers or a stylus to a relative position on a screen.^[7]
TV tuner card: A card that allows the user to view television channels on a computer using an antenna. It can also be used to connect devices such as video game consoles, videocassette recorders, and LaserDisc players, if necessary.

U

Universal Serial Bus (USB): A specification to establish communication between devices and a host controller (usually a personal computer). The USB standard was first finalized in 1996, and has undergone many revisions since then, enabling faster data transfer speeds.
uop cache: A
CISC processor (e.g x86).^[8]
USB 1.x: The first revision of USB, which was capable of transferring up to 12 Mbit/s (megabits per second).
USB 2.0: The second revision of USB, introduced in 2000. It significantly increased the maximum transfer rate to 480 Mbit/s.
USB 3.0: The third revision of USB, introduced in 2008. It provides transfer rates of up to 5 Gbit/s (gigabits per second), more than 10 times faster than USB 2.0.
USB flash drive: A flash memory device integrated with a USB interface. USB flash drives are typically removable and rewritable.

V

video card: An expansion card which generates a feed of output images to a display (such as a computer monitor).
Video Graphics Array (VGA): First released in 1987, this was the last graphical standard introduced by
PC clone manufacturers conformed. Today, it has largely been supplanted by DisplayPort and HDMI
, however, it can still be found as an integrated graphics option in some motherboards.
volatile memory: Memory that requires power to maintain the stored information, as opposed to non-volatile memory. Sticks of RAM are an example of volatile memory.

W

webcam: A video camera that feeds its images in real time to a computer or computer network, often via USB, Ethernet, or Wi-Fi.^[1]^[9]
write-back cache: A cache where store operations are buffered in cache lines, only reaching main memory when the entire cache line is evicted.
write-through cache: A cache where store operations are immediately written to the underlying main memory.
working set: The set of data used by a processor during a certain time interval, which should ideally fit into a CPU cache for optimum performance.

Z

zip drive: The Zip drive is a removable floppy disk storage system that was introduced by Iomega in late 1994. Considered medium-to-high-capacity at the time of its release, Zip disks were originally launched with capacities of 100 MB.

References

^
ISBN 978-1-4239-2702-0
. Retrieved May 25, 2016.

^ "Punched Card System for a Wholesale Hardware". Volume 7. The Punched Card Machine Accounting and Data Processing Semi-annual. 1952. p. 123. Retrieved 18 May 2016.
ISBN 9780824720025
. Retrieved 2016-05-25.

^ "Golden Oldies: 1993 mainboards". Retrieved 2007-06-27.

ISBN 978-1435487383
.

ISBN 978-1133135128
. Retrieved May 19, 2016.

ISBN 9781596822580
. Retrieved May 19, 2016.

^ "micro op cache patent".

ISBN 9780309097918
. Retrieved May 19, 2016.

External links

Dictionary: JESD88 | JEDEC

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Retrieved from "https://en.wikipedia.org/w/index.php?title=Glossary_of_computer_hardware_terms&oldid=1220783587"

[Shelly_Vermaat_2008-1] 
ISBN 978-1-4239-2702-0
. Retrieved May 25, 2016.

[2] "Punched Card System for a Wholesale Hardware". Volume 7. The Punched Card Machine Accounting and Data Processing Semi-annual. 1952. p. 123. Retrieved 18 May 2016.

[Kent_Lancour_2016-3] ISBN 9780824720025
. Retrieved 2016-05-25.

[4] "Golden Oldies: 1993 mainboards". Retrieved 2007-06-27.

[5] ISBN 978-1435487383
.

[6] ISBN 978-1133135128
. Retrieved May 19, 2016.

[7] ISBN 9781596822580
. Retrieved May 19, 2016.

[8] "micro op cache patent".

[9] ISBN 9780309097918
. Retrieved May 19, 2016.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

R

S

T

U

V

W

Z

See also

References

External links