计算机专业英语key-termchapter7

Key Terms-Chapter 7access speedaccess speedMeasures the amount of time required by the storage device to retrievedata and programs.Blu-ray disc(BD)Blu-ray disc(BD)A type of high-definition disc with a capacity of 25 to 50 gigabytes.capacitycapacityCapacity is how much data a particular storage medium can hold and anothercharacteristic of secondary storage.CD(compact disc)CD(compact disc)Widely used optical disc format.It holds 650 MB(megabytes)to 1 GB(gigabyte)of data on one side of the CD.CD-R(CD-recordable)CD-R(CD-recordable)Stands for CD-recordable.This optical disc can be written to only once.After that it canbe read many times without deterioration but cannot bewritten on or erased.Used to create custom music CDs and to archive data.CD-ROM(compact discCD-ROM(compact discread-only memory)read-only memory)Optical disc that allows data to be read but not recorded.Used todistribute large databases,references,and software applicationpackages.CD-RW(compact discCD-RW(compact discrewriteable)rewriteable)A reusable,optical disc that is not permanently altered when data isrecorded.Used to create and edit large multimedia presentations.cloud computingcloud computingData stored at a server on the Internet and available anywhere the Internetcan be accessed.cylindercylinderHard disks store and organize files using tracks,sectors,and cylinders.A cylinder runs through each track of a stack of platters.Cylindersdifferentiate files stored on the same track and sector of differentplatters.densitydensityRefers to how tightly the bits(electromagnetic charges)can be packednext to one another on a floppy disk.disk cachingdisk cachingMethod of improving hard-disk performance by anticipating data needs.Frequently used data is read from the hard disk into memory(cache).Whenneeded,data is then accessed directly from memory,which has a much fastertransfer rate than from the hard disk.Increases performance by as muchas 30 percent.DVD(digital versatile disc or digital video disc)DVD(digital versatile disc or digital video disc)Similar to CD-ROMs except that more data can be packed into the same amountof space.DVDdrives can store GB to 17 GB on a single DVD disc or 17 times the capacityof CDs.DVD playerDVD playerAlso known as DVD-ROM drives.SeeDVD.DVDDVDR(DVD recordable)R(DVD recordable)A DVD with a write-once format that differs slightly from the format ofDVD+R.Typically used to create permanent archives for large amounts ofdata and to record videos.DVD+R(DVD recordable)DVD+R(DVD recordable)A DVD with a write-once format that differs slightly from the format ofDVD R.Typically used to create permanent archives for large amounts ofdata and to record videos.DVD-RAM(DVD random-access memory)DVD-RAM(DVD random-access memory)A high capacity,maximum-performance disc that allows the user to readthe information,write over it,and erase the data if necessary.Used likea floppy disk to copy,delete files,and run programs.It has up to 8 timesthe storage capacity of a CD and also can be used to read CD and DVD formats.DVD-ROM(DVDDVD-ROM(DVDread-only memory)read-only memory)Used to distribute full-length feature films with theater-quality videoand sound.Also known asDVD players.Are read-only.DVD+RW/DVD-RW(DVD rewriteable)DVD+RW/DVD-RW(DVD rewriteable)Another DVD format to record and erase repeatedly.Able to create and readCD discs along with creating and editing large-scale multimediapresentations.enterprise storage systementerprise storage systemUsing mass storage devices,a strategy is designed for organizations topromote efficient and safe use of data across the networks within theirorganizations.erasable optical discerasable optical discOptical disc on which the disk drive can write information and also eraseand rewrite information.Also known as CD-RW or compact disc rewriteable.external hard driveexternal hard driveUses the same technology as an internal hard disk but is used primarilyto complement an internal hard disk by providing additional storage.Theyare typically connected to a USB or FireWire port on the system unit andare easily removed.file compressionfile compressionProcess of reducing the storage requirements for a file.file decompressionfile decompressionProcess of expanding a compressed file.file serverfile serverDedicated computer with large storage capacity providing users access toshared folders or fast storage and retrieval of information used in thatbusiness.flash driveflash driveSeeUSB drive.flash memory cardflash memory cardA solid-state storage device widely used in notebook computers.Flashmemory also is usedin a variety of specialized input devices to captureand transfer data to desktop computers.hard diskhard diskEnclosed disk drive containing one or more metallic disks.Hard disks usemagnetic charges to record data and have large storage capacities and fastretrieval times.head crashhead crashWhen a read-write head makes contact with the hard disks surface orparticles on its surface,the disk surface becomes scratched and some orall data is destroyed.hi def(high definition)hi def(high definition)The next generation of optical disc,which offers increased storagecapacities.internal hard diskinternal hard diskStorage device consisting of one or more metallic platters sealed insidea container.Internal hard disks are installed inside the system cabinetof a microcomputer.It stores the operating system and major applicationslike Word.landlandSeelands and pits.lands and pitslands and pitsFlat and bumpy areas,respectively,that represent 1s and 0s on the opticaldisc surface to be read by a laser.mass storagemass storageRefers to the tremendous amount of secondary storage required by largeorganizations.mass storage devicesmass storage devicesDevices such as file servers,RAID systems,tape libraries,opticaljukeboxes,and more.mediamediaMedia are the actual physical material that holds the data,such as afloppy disk,which is one of the important characteristics of secondarystorage.Singular of media is work attached storage(NAS)network attached storage(NAS)Similar to a file server except simpler and less expensive.Widely usedfor home and small business storage needs.online storageonline storageProvide users with storage space that can be accessed from a Web site.optical discoptical discStorage device that can hold over 17 gigabytes of data,which is anequivalent of several million typewritten pages.Lasers are used to recordand read data on the disc.The two basic types of optical discs are compactdiscs(CDs)and digital versatile or video discs(DVDs).organizational cloud storageorganizational cloud storageHigh-speed Internet connection to a dedicated remote organizationalInternet drive site.pitpitSeelands and pits.platterplatterRigid metallic disk;multiple platters are stacked one on top of anotherwithin a hard disk drive.primary storageprimary storageHolds data and program instructions for processing data.It also holdsprocessed information before it is output.Seememory.RAID systemRAID systemSeveral inexpensive hard-disk drives connected to improve performance andprovide reliable storage.redundant arrays of inexpensive disks(RAIDs)redundant arrays of inexpensive disks(RAIDs)Groups of inexpensive hard-disk drives related or grouped together usingnetworks and special software.They improve performance by expandingexternal storage.secondary storagesecondary storagePermanent storage used to preserve programs and data that can be retainedafter the computer is turned off.These devices include floppy disks,harddisks,magnetic tape,CDs,DVDs,and more.secondary storage devicesecondary storage deviceThese devices are used to save,backup,and transport files from onelocation or computer to another.Seesecondary storage.sectorsectorSection shaped like a pie wedge that divides the tracks on a disk.solid-state drive(SSD)solid-state drive(SSD)Designed to be connected inside a microcomputer system the same way aninternal hard disk would be,but contains solid-state memory instead ofmagnetic disks to store data.solid-state storagesolid-state storageA secondary storage device that has no moving parts.Data is stored andretrieved electronically directly from these devices,much as they wouldbe from conventional computer memory.storage area network(SAN)storage area network(SAN)An architecture that links remote computer storage devices such asenterprise storage systems to computers so that the devices are availableas locally attached drives.storage devicestorage deviceHardware that reads data and programs from storage media.Most also writeto storage media.tape librarytape libraryDevice that provides automatic access to data archived on a largecollection or library of tapes.tracktrackClosed,concentric ring on a disk on which data is recorded.Each trackis divided into sections called sectors.USB driveUSB driveThe size of a key chain,these hard drives connect to a computers USBport enabling a transfer of files;has a capacity of up to 64GB.