Page 120 - TP_iPlus_V2.1_Class8
P. 120

Modem

                               A Modem is a device which is used to transmit data over a network. It is attached to
                               computers that can convert digital signals (to be transmitted over telephone lines)
                               to analog (continuous electrical waves) and convert analog signals to digital signals
                               at the receiving end.
                               Modem  is the  short  form  of  Modulator-Demodulator  where  the  modulator  can
                    Modem
                               convert digital signals to analog and the demodulator does the opposite.
                  Networking Cable

                  Networking cable also known as Ethernet cable is a transmission medium
                  that  allows to  transport information  from one  computer  to  other  place.
                  There are various types of networking cables such as coaxial cable, twisted
                  pair cable and optical fiber cable.
                                                                                                      Ethernet cable
                                             Gateway

                                             A gateway is a network device that allows to data to flow between two
                                             different networks which may use different protocols. It collects data
                                             that is to be sent from one computer, converts it into small packets
                          Gateway            and then sends them to another computer.

                   i +   TYPES OF NETWORKS

                  Different types of networks can be classified on the basis of geographical area they cover. There
                  are five types of networks as follows:                                        Workstation
                  LAN (Local Area Network)

                  LAN is a digital communication system that interconnects a larger
                  number of computers and other peripheral devices within a radius
                  of less than 1 km. This type of network is useful when you want to
                  connect two different departments in a building (e.g., an office, a
                  building or a factory). The hardware, as well as software resources,
                  are shared through LANs. Your school lab is an example of LAN.
                                                                                                                Server
                  MAN (Metropolitan Area Network)                                               Local Area Network

                  MAN consists of two or more local area networks or campus area networks together. It usually spans
                  several buildings in the same city or town. It covers an area ranging from 10 to 100 km. For example,
                  the Internet services provided to users in a city or the ATM network of any area fall under MAN.





                                            LAN                                         LAN







                                                        Metropolitan Area Network


                   118
                         iPlus (Ver. 2.1)-VIII
   115   116   117   118   119   120   121   122   123   124   125