3.1 NETWORK BASIC

What is a Network?

A network is a collection of computers and devices connected together via communications devices and transmission media.

Communication

• • Computer communications is a process in which two or more computers or devices transfer data, instructions, and information.
• Some communications involve cables and wires; others are sent wireless through the air.
  

Communications System

• A sending device that initiates an instruction to transmit data, instructions, or information.
• A communications device that connects the sending device to a communications channel.
• A communications channel, or transmission media on which the data, instructions, or information travel.
• A communications device that connects the communications channel to a receiving device.
• A receiving device that accepts the transmission of data, instructions,or information.
  
  

Communication Device / Transmission Media

Communication Device 

* Modem

* Router

* Hub/Switch

* NIC/LAN card

Sending/Receiving Device

* Mainframe

* Computers

* Servers

* Desktop computers

* Notebook computers

* Smart phones

* Internet enabled 

portable media players

* Handheld game consoles

* GPS receivers.

Communication Channel/Transmission Media

• • Physical Transmission Media - telephone lines, power lines, cable television, underground lines.
• • Wireless Transmission Media - microwave, satellites, Bluetooth, infrared.

Advantages of using a Network

* Facilitating communications
* Sharing hardware
* Sharing data and information
* Sharing software
* Transferring funds

Disadvantages of using a Network

* Viruses

* Network failure

* Slow service

* Cost

* Expert support require