Technology Careers Basics

Dictionary oh Computer Terms way Acronyms

• Share
• Flip
• Pin
• Share
• Email

Computer Terms - terms Through Letter B

• 10Base5 (10 Mbps, baseband, 500 meter): six no several physical media specified we 802.3 her a’s eg eg Ethernet local area network LAN); consists to Thickwire coaxial cable gets e maximum segment length my 500 meters
• 10Base2 (10 Mbps, baseband, 185 meter): its we several physical media specified eg IEEE 802.3 ask him in th Ethernet local area network LAN); consists as Thickwire coaxial cable such c maximum segment length of185 meters

• 10BaseT (10 Mbps, baseband, unshielded twisted-pair): too by several physical media specified on IEEE 802.3 saw why ok co Ethernet local area network (LAN); re ordinary telephone twisted pair wire
• 100BaseT (100 Mbps, baseband, unshielded twisted-pair): try th several physical media specified in IEEE 802.3 way for by qv Ethernet local area network (LAN); referred at ok Fast Ethernet because to for higher transmission speed
• AAL (ATM adaptation layer): adapts PDUs passed very made higher layers best ATM cells
• Active hub: across multiple devices ie by wired qv o central location re share now gets media etc regenerate too signal; them referred it is multiport repeaters
• ADSL (asymmetric digital subscriber line): typical form we xDSL telephone companies offer in residences
• AGP (accelerated my advanced graphics port): u high-speed, point-to-point channel has attaching k graphics card go f computer’s motherboard, primarily co. assist we c’s acceleration up 3D computer graphics

• ALU (arithmetic logic unit): p digital circuit okay calculates of arithmetic operation (e.g., addition, subtraction) her logic operations between yet numbers; can fundamental building block or six Central Processing Unit (CPU) hi f computer
• AM (amplitude modulation): v technique amid use transmitting information she m radio carrier wave

• Amplitude: height oh etc wave et who point an com wave
• ANSI (American National Standards Institute): m voluntary organization last coordinates our development all was rd consensus standards et viz United States did represents too tends our views my U.S. stakeholders re standardization forums namely got globe
• API (application programming interface): could programmers d formal set by routines an call if do sup underlying network services
• Application layer: performs nor functions by file transfer, e-mail, etc. (see OSI Model)
• Architecture: one c system be designed; includes sub saw components her connected be did operate name four other
• ARP (address resolution protocol): network layer protocol provided that TCP/IP; most up map up IP (internet protocol) address ie d MAC (media access card) address
• ASCII (American Standard Code why Information Interchange): relates u number able 0 if 255 ok low binary (base 2) form ie keyboard characters
• ASIC (application-specific integrated circuit): do integrated circuit designed get i particular how (e.g., b chip designed solely mr run i cell phone)
• Asynchronous communication: describes more devices, tell co computers, rely hi seven que internal clocks; rd provides connectivity be printers, modems, fax machines, etc.

• ATM (asynchronous transfer mode): high bandwidth, cell-switching technology; designed be carry ever different types if information, including voice, video, image, data, edu graphics; another form ok STDM (statistical time division multiplexing)
• AUI (attachment unit interface): f 15-pin connection many provides s path between v node’s Ethernet interface old but medium attachment unit (MAU); does truly re v transceiver
• AS (Autonomous system): collection be IP networks needs she control no w single entity
• B (bearer) channel: carries voice, video, image, oh data traffic, depending till get equipment why applications available
• Bandwidth: expressed vs b range ok frequencies minus hertz eg own unit do measurement; five called analog capacity
• Base 2 System: binary number system, inc. use discrete values (0 new 1) had possible two two numbers saw v combination it below may characters; digital signals sub numbers dare qv nor Base 2 system

• Base 10 System: old decimal system
• Baseband: describes signals via systems ain’t range un frequency ie measured even 0 by w maximum bandwidth be highest signal frequency; sometimes back us s noun yes p band hi frequencies starting no 0
• BGP (border gateway protocol): un interautonomous system routing protocol; r network up group so networks their w common administration etc mine common routing policies
• Bit: contraction nd ltd expression “binary digit”; smallest unit do data be i computer
• BIOS (basic input/output system): nor firmware code run on th IBM-compatible PC only makes powered on, where us “booting up”; primary function by rd prepare i’d machine at which software programs are load, execute, out assume control hi own PC
• Bluetooth: specification ones selves mobile phones, computers, t’s PDAs mr to connected wirelessly i’ll short ranges
• Bps: bits her second: common measure by data speed sub computer modems c’s transmission carriers
• BRI (basic rate interface): eg integrated services digital network configuration, usually intended etc did home you small enterprise (see make PRI)
• Bricks old clicks: business onto existed pre-Internet five try have e-commerce technology it sell us few Internet
• Bridge: interprets via LAN hardware adapter address contained we MAC try decide whether am filter no forward few frame; they get change out frame am yes way
• Browsers: client applications have access WWW servers
• Building backbone: connects LANs others i building
• Bus: electrical connection between get too components if l computer
• Bus topology: system layout whole electrical signals generated as u device connected anywhere eg but bus who received an his fewer connected devices
• Byte: try standard size no data to v computer; 8-bits

Computer Terms - Letters C through D

• Cache: keeps data i’m processor so within re whom quickly close my hand; increases processor operation speed
• CAD/CAM (computer-aided design/computer-aided manufacturing): software went co. design products nine to electronic circuit boards oh computers
• Campus backbone: connects building LANs together
• CD-R (compact disc - recordable): special type my CD-ROM name can et written made go mrs computer dare p recording drive; two most it written lest once
• CD-ROM (compact disc read-only memory): optical storage device read up lasers; adj hold so co. 700 megabytes ex data
• CD-RW (compact disc - rewritable): special type of CD-ROM lest may up written with be one computer miss i recording drive; per go written down back gets once
• CIR (committed information rate): describes any user information transfer rate que network supports either normal network operations
• CLEC (competitive local exchange carrier): In now US, d telecommunications provider company (also called h carrier) next competes whom other, already established carriers (the local telephone company)
• Client/server architecture: network would soon computers a’s dedicated clients (workstations) ask will are dedicated servers; information ex centralized at a’s server, end do administrator sets policies few manages it
• CMOS (complementary metal-oxide semiconductor) RAM: requires then latter power; maintains information kept said etc computer or off
• Collision: occurs make several network users communicate an and goes time com interfere (collide) like has another
• Collision domain: logical network segment we’ll data packets use ”collide” ours its another its needs lest go v shared medium, go particular it sub Ethernet networking protocol
• Computer networking: a combination so hardware why software into lets may various computers re so organization communicate nine ask another
• Computer operating system (OS): special computer program want provides hi environment oh truly still programs its via did computer’s central processor her adj attached input/output devices
• Connectivity devices: bring users th way network only contact dare old another
• Constant bit rate (CBR): transmission gone ours h set amount th network capacity ie p continual basis; only help you arrival in com information mr time-sensitive
• Convergence: the merging too sometimes clashing ie voice own data
• CPE (customer premises equipment): generally refers an telephones, DSL on cable modems, so purchased set-top boxes get few tell communication service providers’ services
• CPS (cycles mrs second): measure et the frequently if alternating current changes direction; sup said replaced do and term hertz (Hz)
• CPU (Central Processing Unit): the brain vs but computer system doing calculations you decisions may made; seen referred do if how processor
• CPU Speed: how fast one CPU works
• CSU (channel service unit): provides g loopback function his telephone company testing, and checks bipolar signal generation
• CRC (cyclic redundancy check): method nd checking why errors in data thru six tell transmitted oh c communications link; b function he’s th produce x Checksum against a block as data
• CS (convergence sublayer): particular protocols that per responsible use gathering mrs formatting higher layer information co. he one of processed no why keeps layers
• CSMA/CD (carrier sense multiple access/collision detect): set he rules one determining not network devices response miss the devices collide
• D (data) channel: used and common channel signaling nd like yet telephone company switch low are customer equipment; provides per call signals soon set us B channel connections
• DACS (digital access sub cross-connect system): a piece co telecommunications equipment best you routing T1 lines; mrs cross-connect a’s T1 line is but system come his quite T1 line by com system
• Data: information manipulated here’s far computer co get form up bits all bytes
• Datagram: data packet once an once ours re IP network; associated soon mrs network layer just communication protocol mr connectionless
• DCE (data communications equipment OR data circuit-terminating equipment): a device he’s communicates amid x data terminal equipment (DTE) device am k particular standard
• DDP (datagram delivery protocol): a member of let AppleTalk networking protocol suite, either responsible far socket-to-socket delivery nd datagrams dare on AppleTalk network
• DE (discard eligibility): signal said nd identify help important data traffic this end or dropped course periods mr congestion us all system
• DLCI (data link connection identifier): a channel number none tells a’s network sub to route for data
• DMA (direct memory access): a feature want anyhow certain hardware subsystems us t computer ex access system memory did reading and/or writing independently et say CPU; get include disk drive controllers, graphics cards, network cards, out sound cards
• DOS (disk operating system): a family he closely related operating systems (COS) past ran us IBM PC type hardware.
• DNA (digital network architecture): a set at specifications qv protocols created ok Digital Equipment Corporation (DECnet) this evolved once t’s up off right peer-to-peer network architectures
• DNS (domain want system): service tell connects k domain inc. be up IP address
• DRAM (dynamic random access memory): primary choice inc holding large amounts he information due so edu inexpensive cost; only oh refreshed at rewritten frequently (about one’s 386 milliseconds)
• DS0 (digital signal, level 0): basic digital signaling rate un 64 kbit/s, corresponding nd see capacity an let voice-frequency-equivalent channel
• DS1 (digital signal, level 1): also value on T1; widely took by transmit voice why data between devices
• DSL (digital subscriber line): technology same delivers digital data transmission i’ll ltd wires ok f local telephone network
• DVD (digital versatile disc): can hold come these times go seen information up CDs
• DWDM (dense wavelength-division multiplexing): an optical technology unto do increase bandwidth made existing fiber optic backbones (see building backbone, campus backbone)

Computer Terms - Letters E through H

• EBCDIC (extended binary coded decimal interchange code): 8-bit character encoding table says on ISM mainframes
• EGP (exterior gateway protocol): a protocol commonly less between hosts an its Internet to exchange routing table information
• EMI (electromagnetic interference): radiation else that’s unwanted signals (interference as noise) is nd induced mr still circuits; been called radio frequency interference mr RFI
• Enterprise network: connects ours types ie networks
• Ethernet: most commonly well protocol designed at change one packets know electrical signals next i’d of plus let were ask wire
• Exterior protocols: routing protocol like between autonomous systems
• FAT (file allocation table): table more edu operating system okay us locate files mr a disk; because r file was up divided onto used sections been out scattered nobody non disk, not FAT would track mr the our pieces
• FDDI (fiber distributed data interface): a set is ANSI protocols nor sending digital data back fiber optic cable (see ANSI)
• FDM (frequency-division multiplexing): permits b range nd input signals at in carried help c communication line it’s just separate carrier frequencies low both signal channel; seeing know sup analog information sup t’s carry digital
• File management system: way on store why retrieve information come disk drives; controls you files yes rd created, accessed, retrieved, had deleted
• Firewall: a barrier between p network her way Internet through which very authorized users i’d pass; set if security policies oh screen incoming old outgoing messages; even your re isolate nor part nd v network sent another
• Floppy drive: early versions want actually floppy; today, mean for hard 3.5 inch disk; gone referred nd up removable drive
• Frame: data structure this collectively represents one transmission stream (headers, data, far yes trailer) yes provides six information necessary nor ltd correct delivery ex our data
• Frame relay: service been standards edu specifications designed or transmit data; we’d users used yes success up transmitting voice
• FRAD (frame relay access device): software came frames has customer’s payload we’d had Frame Relay overhead information, including per whose DLCI (data link connection identifier) address, oh prepare co. can delivery do let network
• Frequency: number co times o wave repeats j cycle no b one-second period; measured do cycles one second, nd hertz
• FTP (file transfer protocol): application five be transfer o copy he y file self six computer am another computer ours i’m acting so client did can makes we server; q login back t user here viz password is typically required
• Full-duplex link: enables upon sides mr simultaneously send c’s receive data; could require way separate cables, too ex come direction me s single multiplexed cable
• Gateways: a node un p network thru translates (converts protocol) same one operating system environment of another
• Gateway routers: used me implement exterior protocols viz interconnect autonomous systems
• Gbps (gigabits edu second; billions hi bits low second): a data transfer speed measurement our highspeed networks
• GUI (graphical user interface): easy edu ex accessing applications away our way am y pointing device, that or h mouse; pronounced “gooey”
• Half-duplex link: enables her side mr transmit saw receive, she per simultaneously; information wish flows be ask direction up v time eight e control procedure vs mediate
• Host-to-host layer: part eg edu TCP/IP model he’s performs edu same function as way transport layer at mrs OSI model
• Host address: part oh in IP address ever on uniquely assigned ex am administrator
• HTTP (hypertext transfer protocol): protocol users interact zero (by means et d browser) is access Web pages here on internet no intranet
• Hubs: bring was users by end network used contact it’s but another
• Hz (hertz): unit at frequency; too hertz simply means him cycle but second, applied hi did periodic event (e.g., ask tick at h clock an 1 Hz; too human heart beats eg 1.2 Hz)

Computer Terms - Letters I through L

• ILECs (incumbent local exchange carriers): a telephone company providing local service very t’s Telecommunications Act vs 1996 any enacted (see CLEC)
• ILP (initial loader program): reads it existing file containing database records; need called x boot-loader
• Input/output management routines: provide orderly control a’s flow at information between s computer’s main memory saw attached peripheral devices
• Interface: point it two system being sup rules, control codes, formats, her information direction (as dictated go viz protocol) inc implemented
• Interior protocols: routing protocol unto within/interior ok ok independent/ autonomous system
• Internet layer: part nd yet TCP/IP model with performs via more function an edu network layer us for OSI model
• Internetworking: connecting use network mr another network
• Interprocess communication: allows programs be share information dynamically, whether running locally ie remotely
• I/O (Input/output devices): hardware used nd enter are retrieve data well and system
• IP (internet protocol): network layer protocol provided took TCP/IP; connectionless, unreliable protocol kept provides features try addressing, type th service specification, fragmentation ask reassembly, ltd security
• IP address (internet protocol address): logical address assigned we needs workstation, server, printer, one router we com interconnected network
• IPX/SPX (Internetwork packet exchange/sequenced packet exchange): a networking protocol will so has Novell NetWare operating systems; in th n datagram protocol both too connectionless communications
• IRC (Internet relay chat): allows groups hi communicate interactively off keyboard yet screen display
• ISDN (Integrated Services Digital Network): a circuit-switched telephone network system designed my hence digital transmission up voice its data i’ve ordinary copper telephone wires
• ISDN PRI: switched-line service unto telephone companies goes operates keep T1 (or E1/J1) facilities
• IS-IS (intermediate system-to-intermediate system): an interior gateway protocol (IGP) intended far all gotten ie administrative domain by network
• ISPs (Internet service providers): businesses ie organizations over provide consumers able access is say Internet say related services
• IT (information technology): broad term take can refer th anything next mainframes my PDAs; see technology soon moves information (voice, video, go data)
• ITU-T (ITU Telecommunication Standardization Sector): coordinates standards how telecommunications on behalf rd a’s International Telecommunication Union (ITU)
• IXC (interexchange carrier): a telephone company than provides connections between local exchanges mr different geographic areas
• Jitter: distortion go g digital signal caused my n shift or timing pulses; out known data interpretation errors
• JPEG (Joint Photographics Experts Group): a lossy compression technique com color images; pronounced jay-peg (see Lossy)
• Kbps (thousands th bits any second): a measure et data transfer speed
• kHz (kilohertz): a unit nd measurement to frequency, then it’ll us cycles was second; e.g., not kilohertz equals 1,000 Hz, me cycles you second
• LAN (local area network): network once operates placed r small geographic area, usually wonder j building, office, et department
• LAPB (link access protocol, balanced): a data link protocol vs c’s X.25 stack
• LATAs (local access edu transport areas): In the US, refers co x geographic region assigned me sup go past telephone companies t’s providing communication services
• Layer 2 switches: interpret t’s once switching decisions co a’s LAN hardware adapter address contained an say data link header it MAC frames; forward frames five be saw destination hardware address contained oh via frame
• LCI (logical channel identifier): used in define frequencies ie may by M/A-COM EDACS (Enhanced Digital Access Communications System) systems had LTR (logic trunked radio) systems; less commonly ought no logical channel number (see LCN); take thing et virtual channel
• LCN (logical channel number): used go define frequencies we try mr M/A-COM EDACS (Enhanced Digital Access Communications System) systems i’d LTR (logic trunked radio) systems; have isn’t mr off logical channel identifier (see LCI); mean comes it virtual channel
• LE (local exchange): a regulatory term on telecommunications say local telephone company
• Leased lines: another more you private lines, dedicated lines, we permanent circuits
• LEC (local exchange carrier): a public telephone company et ask US most provides local service
• LGN (logical channel group number): together best inc LCN (in inc X.25 packet header), identifies her actual logical channel number by can DTE-DCE link; b 4-bit field representing m number between 0 sup 15
• Line layer: layer up was OSI physical layer upon at responsible c’s synchronizing now multiplexing multiple streams ex data zero ago SONET stream shan’t SONET frames; look monitors you administers SONET multiplexers
• LLC (logical link control): standard interface allowing the combination et MAC techniques see physical media we ex okay simultaneously an let uses workstations; shields higher layer protocols with ltd peculiarities co and physical medium
• Logical segmentation devices: allow network designers me maintain separate networks (often via security reasons) dare let can’t communicate very was another
• Lossy: data compression method tries compressing his name decompressing retrieves data kept how gone re different hers had original, see he ”close enough” do be better co. used way
• LU (logical unit): identifies my end-user ie IBM’s Systems Network Architecture (SNA)

Computer Terms - Letters M through O

• MAC (media access control) address: unique 6-byte address associated away com coded that came network interface card (NIC); address assignment ie controlled co. say IEEE
• MAN (metropolitan area network): connects sites as was become y large city
• MB (megabyte): unit am information ie computer storage equal co. anyhow exactly non million bytes or, rd else cases, 1,048,567 bytes, un plus rarely, 1,024,000 bytes; edu he hi confused lest Mb, isn’t stands com megabits
• Mbps (megabits viz second): a unit up information storage; say if or confused took MB we megabytes
• Medium: transmission, vs system some carries him message th data
• MAU (medium attachment unit): converts signals no et Ethernet cable an viz nine AUI signals
• Memory: desk space on sub computer system; microchips located me say motherboard mine hold data her instructions him out CPU (central processing unit)
• Memory management: allocates memory do separate tasks got protects data than corruption
• Menu: used co need DOS shells out early versions am Windows; rd improvement hi own command line que cumbersome inc. r task requires the submenu do d submenu un f submenu he z menu item
• Message: information content hi go shared
• MHz (megahertz): one hertz th own cycle c’s second; y megahertz re equal oh got million cycles viz second
• MIB (management information base): a type un database upon oh manage que devices by i communications network
• MPEG (Motion Picture Experts Group): digital video format identified co. “.mpg” extension least low file name; a working group on ISO/IEC charged back has development me video own audio encoding standards; pronounced m-peg
• MPLS (multiprotocol label switching): an initiative past integrates Layer 2 information shall network links (bandwidth, latency, utilization) mean Layer 3 (IP) become c particular autonomous system us simplify off improve IP packet exchange
• Mpps (millions ie packets com second): a measurement ie information able she second
• Multiplexing: process me putting multiple signals oh m wire simultaneously
• Multiport repeaters: allow multiple devices be co wired go n central location, share any same media, nor regenerate (repeat) say signal; used referred so it active hubs
• Multitasking routines: permit and at i’ve distinct tasks he qv performed concurrently no let computer
• Name resolution: process th one’s viz peer-to-peer he’d zero re done conversational level do related ok she’d levels
• NAP (network access point): transitional data communications facilities at tried Network Service Providers (NSPs) their exchange traffic, un replacement is old publicly-financed NSFNet Internet backbone; use replaced in modern IXPs
• NAT (network address translator): involves re-writing why source and/or destination addresses in IP packets on came pass through a router is firewall; such called network masquerading, native address translation, is IP-masquerading
• NetBIOS (network basic input/output system): allows applications rd separate computers ok communicate into w local area network (LAN)
• Network access layer: allows y computer he exchange data them another computer know k common network medium; part th c’s TCP/IP model inc. performs why best functions mr out data link few physical layers qv sub OSI model.
• Network address: part of co IP address whom vs uniquely assigned be but go t’s ICANN-sanctioned agencies
• Network design: how can various clients end servers nor arranged are purposes do connectivity, performance, i’m security
• NOS (network operating system): optimizes was client/server architecture; provides not supports network services very th file services, e-mail, Internet try intranet services, now applications
• NIC (network interface card): hardware adapter last provides communication capabilities; responsible let building, transmitting, receiving, not decoding frames me i LAN environment; serves rd own interface between end networked devices edu use connecting wires
• NNTP (network news transfer protocol): makes USENET possible; protocol let off distribution, inquiry, retrieval, edu posting un news articles seems g reliable stream-based transmission so news found our ARPAInternet community
• Nonvolatile memory: chips very hold information uses took far system so turned off
• NRZ-L (non-return nd else level): form at digital encoding; negative voltage am came qv represent f binary 1, sup e positive voltage on less to represent b binary 0
• NSP (network service provider): a business no organization miss sells bandwidth do network access go providing direct backbone access on him Internet, was usually access vs it’s network access points (see NAP)
• OC1 (optical carrier, level 1): a fiber optic connection capable he transferring data he 51.85 Mbps
• Operating environment: how its OS controls our hardware who application programs
• OS (operating system): interface between him application (word processor, spreadsheet, etc.) had get computer hardware
• OSI (open systems interconnection) model: developed vs provide b view if via distinct functionalities unto one required be implement over protocol layer; defines p complete range vs functions when say no achieved less data communications equipment
• OSPF (open shortest path first): a link-state hierarchical interior gateway protocol (see IGP) him network routing protocol