5. A router is adevice thatforwardsdatapacketsbetweencomputernetworks.
This createsanoverlayinternetwork,asa routeris connectedtotwoormoredatalinesfrom
differentnetworks.Whena datapacketcomes in one ofthe lines, the routerreadsthe
addressinformationin the packettodetermine itsultimatedestination.Then, using
informationin itsroutingtableorroutingpolicy,it directsthe packetto thenextnetworkon
its journey.Routersperformthe "trafficdirecting" functionson theInternet.A datapacketis
typicallyforwardedfromone routertoanotherthroughthenetworksthatconstitutethe
internetworkuntilit reachesitsdestinationnode.
7. A modem(modulator-demodulator)is adevice thatmodulatesananalogcarriersignal to
encodedigital informationanddemodulatesthesignal todecodethe transmittedinformation.The
goal is toproduceasignal thatcanbetransmittedeasily anddecodedto reproducethe original digital
data.Modems canbe usedwith anymeans oftransmittinganalogsignals, from light emitting
diodestoradio.A common typeofmodem isone thatturnsthedigital dataofacomputerinto
modulatedelectrical signal fortransmissionover telephonelines anddemodulatedbyanothermodem
atthereceiver sidetorecoverthe digital data.