The document discusses computer networks and their components. It defines a computer network as a set of computers connected together to share resources like printers. The key components of a network include network interface cards, switches, routers, servers, firewalls and network media. Common applications of networks mentioned are file sharing, hardware sharing, network gaming, application sharing and voice over IP. The document provides examples of networks like the internet and discusses the purpose of creating computer networks to communicate and share data and resources.

1. SNS COLLEGE OF ENGINEERING
Kurumbapalayam(Po), Coimbatore – 641 107
Accredited by NAAC-UGC with ‘A’ Grade
Approved by AICTE, Recognized by UGC & Affiliated to Anna University, Chennai
Department of Information Technology
Course Name : CS8591 Computer Networks
III Year / V Sem
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Unit 1: Introduction and Physical Layer
Topic 1 : Networks

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Networks doesn’t Exist
Multinational Company
Local Office
Postal Service
Fax
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Networks doesn’t Exist
Old Data
Cumbersome
Human Error
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Office Interconnected
Multinational Company
Central Location
Management Team
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Office Interconnected
Multinational Company
Location
Productive
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Purpose of Computer Network
INTRODUCTION
To Communicate
To share data or information
To share resources
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Example
Accessing the Phone
Mobile Shopping
Credit card
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Example
ATM
Car Maintenance
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The Networked World
➢An excellent example for network is Internet
➢Internet is our greatest network
➢Connects millions of people and applications all over the world
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Computer Networks
Set of computers connected together for
the purpose of sharing resources.
Ex: Printer
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Network Components
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Network Components
➢Network Interface Card, it is also called network
interface controller, network adapter or LAN
adapter.
➢A computer hardware component that connects a
computer to a computer network.
➢Switch, a device in a computer network
that connects other devices together
➢Using packet switching to receive and
forward data to the destination device.
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13. Network Components
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➢Network Media, not a device, but it is
used to connect different devices in a
network together.
➢Printer, Scanner etc.
➢A router is a networking device that
forwards data packets between computer
networks.
➢Perform the traffic directing functions on
the Internet
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14. Network Components
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➢Network Protocol, Formal standards and
policies made up of rules, procedures and
formats that defines communication
between two or more devices over a
network.
➢Network Packet, a packet consists of
control information and user data;
➢The latter is also known as the payload.
➢Control information provides data for
delivering the payload
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Network Components
➢Server, provides variety of
services and functionality to
the users and systems on the
network
➢Firewall, is a security device, computer
hardware or software.
➢Protect your network by filtering traffic and
blocking outsiders from gaining unauthorized
access to the private data on your computer.
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16. Network Components
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➢Virtual Private Network, is an
encrypted connection over the
Internet from a device to a network.
➢An Internet Protocol address (IP address)
is a numerical label assigned to each device
connected to a computer network that uses
the Internet Protocol for communication.
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Network Components
➢(Domain Name System), is the phonebook of the
Internet
➢For example, when a Web address (URL) is typed
into a browser, DNS servers return the IP address of
the Web server associated with that name.
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Applications
File sharing
Hardware sharing
Network gaming
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APPLICATIONS
Application sharing
User Communication
Voice over IP
(VoIP)
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Puzzle
Identify the applications of CN with the help of the pictures
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Source of Information
➢ https://www.youtube.com/watch?v=m9evUZtkEAc
➢ https://www.youtube.com/watch?v=eDLXs4L_ayA
➢ https://www.youtube.com/watch?v=gVrXLq5E-CQ
➢ https://www.youtube.com/watch?v=mpQZVYPuDGU
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22. THANK YOU !
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