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Modem

                 It  stands for  Modulator-Demodulator.  A  modem is a
                 peripheral  device which modulates (converts analog
                 signals to digital signals) from the transmitting workstation
                 and demodulates (converts digital signals into analog signals) at the recipient’s workstation. The
                 sending and receiving ends of the communication must have a modem. Nowadays mobile phones
                 have inbuilt modem devices that help to browse internet. Modems are of two types: internal and
                 external. An internal modem is located inside the CPU box, just like the motherboard plate. On
                 the other hand, an external modem is a separate device that you can connect to the computer
                 with the help of a USB port. It generally contains indicators in the form of small lights.
                 Ports


                 Computer  ports  are  an  interface  between  the  computer  and  peripheral  devices like mouse,
                 keyboard, monitor, printer, speaker, flash drive, pen drive, etc. A computer port acts as a point of
                 connection where the cable or plug from the peripheral device can be plugged to facilitate data
                 flow from and to the device.
                 A computer port is also called a communication port as it facilitates communication between the
                 computer and its peripheral device. Based on the type or protocol used for communication,
                 ports can be categorized as Serial Ports and Parallel Ports.

                 •  Serial Port: It is an interface  through which peripherals  can be
                   connected using a serial protocol which involves the transmission of
                   one bit of data at a time over a single communication line. Generally,
                   serial ports are used to connect the modems.


                                    •   Universal Serial  Bus (USB)  Port: It is  also  known as a standard  cable
                                       connection interface, and is to connect USB devices and provide power
                                       supply to the devices connected to it. Mouse, keyboard, etc., are connected
                                       to the computer with the help of USB ports.

                 •  Parallel Port: It is an interface through which the communication
                   between a computer and its peripheral device takes place in a
                   parallel  manner  i.e.,  data is transferred  in or  out  parallely  or
                   simultaneously using more  than  one  communication  line or
                   wire. Printer port is an example of parallel port.

                                     •  PS/2 Port: It  was  used to  connect  the  keyboard  and  mouse with  the
                                       computer. Now, USB ports are used in place of PS/2 ports.



                 •  Video Graphics Array (VGA) Port:  It is found in computers, projectors, video
                   cards and many TVs. The connector is called DE-15. It is also similar to the
                   serial port. The only difference is that it has holes instead of pins.  It is a D
                   shaped sub connector consisting of 15 pins in 3 rows. With the advancement
                   in technology, HDMI and Display ports are used in place of VGA ports.



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                                                                              Computer—Hardware Components
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