Summary

desktop computer 7crosstalk Interfering energy, such as electromagneticinterference (EMI), that is transferred from onecircuit to another.current (I) The flow of electrons in a conductorthat is measured in amperes.customer-replaceable unit (CRU) A componentthat customers may install at their location.cylinder All the tracks on a hard disk with thesame number. Collectively, the same track on allplatters of a multiplatter hard drive.Ddaily backup Backs up only the files that are modifiedon the day of the backup. This backup does notreset the archive bit.data backup Information on a computer stored onremovable backup media that can be kept in a safeplace. If the computer hardware fails, the data backupcan be restored so that processing can continue.database An organized collection of data that canbe easily accessed, managed, indexed, searched, andupdated.data link layer Layer 2 of the Open SystemsInterconnection (OSI) reference model. This layerprovides reliable transit of data across a physicallink. The data link layer is concerned with physicaladdressing, network topology, line discipline, errornotification, ordered delivery of frames, and flowcontrol. The IEEE has divided this layer into twosublayers—the MAC sublayer and the LLC sublayer,sometimes simply called link layer. Roughly correspondsto the data link control layer of the SystemsNetwork Architecture (SNA) model. The OSI referencemodel includes the application layer, presentationlayer, session layer, transport layer, networklayer, data link layer, and physical layer.data transfer rate Refers to how fast the computercan transfer information into memory.default gateway A node or router on a networkthat provides access to another network or theInternet.default installation An installation that requiresminimal user interaction. Also called a typical installation.default printer The first option that an applicationuses when the user clicks the printer icon. The usercan change the default printer.DEFRAG A command that rearranges the data andrewrites all the files on the hard drive to the beginningof the drive. This makes it easier and faster forthe hard drive to retrieve data.denial of service (DoS) A form of attack that preventsusers from accessing normal services, such ase-mail or a web server, because the system is busyresponding to an abnormally large number ofrequests. DoS works by sending an abundance ofrequests for a resource. This causes the system tooverload and stop operating.desktop A metaphor used to portray file systems.A desktop consists of pictures, called icons, thatshow files, folders, and any resource available to auser in a GUI operating system.desktop computer A type of computer designed tofit on top of or under a desk. Desktop computers arenot mobile like laptop computers.