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Chapter 5 + 6
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Chapter 5
NETWORK
Chapter 5
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What is a Network?
• *A network is a group of connected computers that
allows people to share information.
• For example, instead of linking each computer to its own
printer, all computers can be linked to a common printer
for shared access by multiple users
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Types of Networks
The three basic types of networks include:
1-Local Area Network (LAN).
2-Metropolitan Area Network (MAN).
3-Wide Area Network (WAN)
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1-Local Area Network (LAN)
- Network in limited geographical
area such as home or office
building
- LAN covers a small region of
space typically a single
building, schools or at home
- Rarely are LAN computers more
than a mile apart.
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2-Metropolitan Area Network (MAN)
- A collection of LANs with the same
geographically area for instant a city.
- It covers larger geographic areas , such as
cities or school districts.
- local libraries and government agencies
often use a MAN to connect to citizens and
private industries.
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3-Wide Area Network (WAN)
-Wide Area Networks (WANs) connect
larger geographic areas, such as bank
branches or the world.
- Dedicated transoceanic cabling or satellite
uplinks may be used to connect this type of
network.
- Can be a collection of LANs or MANs or the
mix of two with a very large geographical
area for instant a country or even beyond
the
border.
-The best known WAN is the internet
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Differentiate between the three types of computer
networks
(Question & Answer session)
1. Collection of computers and devices connected via
communications devices and transmission media
Network
2. Network in limited geographical area such as home
LAN
3. Connects LANs in city or town
MAN
4. Network that covers large geographic area using
WAN
or office building.
many types of media
5. What is the world’s` largest WAN ?
Internet
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INTERNET
Chapter 6
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What is the Internet ?
-The internet is a communication system that allows
computers around the world to communicate and
exchange of the data with each other.
-The Internet, also called the Net, is an international
network that connects many thousands of networks and
millions of computers across the world. Used by many
people and organizations to communicate and share
information, the Internet links computers of different
sizes and types.
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The short history of the internet
-The internet started at 1969 it was called (ARPANET)
which is the Advanced Research Projects Agency.
-The goal was to allow scientists at different to actions to
share information .Also to function if part of the internet
was disabled.
-The internet started with four nodes in 1969,and became
1000 nodes in 1984, nowadays more than 200 million
nodes in the internet.
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Connection to the Internet
There are two main methods to connect to the internet:
1- Slow speed technology :
Which is ( dial up access modem) in your computer uses a
standard telephone line.
2-High speed connection :
Which is the (digital subscriber line(DSL)cable telephone
internet services modem , or through wireless or satellite
modems .
The connection is always running .
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World Wide Web (WWW)
- World Wide Web (WWW) : is a Collection of electronic
elements (documents) .
- Each document is called a web page , which can contain
text ,graphics ,sound ,video , and more.
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Web browser
Web browser : is a program that allow users to view
web pages.
Example:
-Microsoft Internet explorer.
-Opera
-Firefox
-Chrome
-Safari
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Internet services
1- E-mail
2-Newsgroups.
3-Telnet.
4-Distance Learning
5-Banking services of transfer and bill payment
6-E-library
7-E-commerce