The Internet

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26 Οκτ 2013 (πριν από 3 χρόνια και 9 μήνες)

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The Internet

The Internet is a
network
of millions of computers all over the world that are
connected
with each
other and work together. It started in the USA in the 1970s and 1980s as a
government
project. The
World Wide Web , which
came up
in the middle of the 1990s , made the Internet easy to use for
everybody.

Education

,
business
,
entertainment
and
government
are changing as the Internet moves into
the lives of more and more people.



Networks

A
network
is a group of computers that are

connected
to each other by cables or telephone lines.
Most networks have one or more servers, more powerful computers that hold programmes and other
data
. A group of computers that are in the same room or building is usually called a LAN (Local Area
Netwo
rk). A Wide Area Network (WAN)
connects
computers that are
far apart
.



How the Internet Works

All computers that are
connected
to the Internet must speak the same language. It is called TCP/IP
(Transmission Control Protocol/ Internet Protocol). and
make
s sure
that information sent by one
computer
arrives
at a
certain destination
.

Every computer on the Internet has an IP address. It is made up of 4 groups of up to 3 numbers,
separated by a
dot
. For example : 207.46.230.219 . Such an IP number can only
occur
once in the
whole
world. Because such numbers are difficult to remember, computers have names, like “

www.news.at”
or “

www.cnn.com”

. If we want to get information from a
certain
computer we must
type
in its name. Special computers on the net have t
he job of turning names into numbers which
computers can understand. Such computers are called Domain Name Servers (DNS).




When a computer sends
data
to another computer it is
broken up
into many small
packets

. These
small
packets
can travel
on their
own
. When they get to their
destination

, the packets are put
together again in the
right order

. Each of them may take different
routes
and they pass by many
other computers to get there.



Internet services

1.

E
-
Mail is the oldest and most
popular
form o
f
communication
between computers. People send
messages
to each other using an email address . Such an
address has two parts: the
user name
of a person and the
name of the computer itself. These two parts are
separated
by the “@”.


Structure of an email address

2.

Newsgroups are discussion
boards
that let many people all
over the world
post messages
on a
certain topic

. These
messages
are saved and people can read them over and
over again.

3.

Chats are live Internet meetings in which you

type
a
message into your keyboard and it
appears immediately
on
the
screens
of other chatters. Groups of people meet in chat
rooms where they talk about
subjects
they like.

4.

The World Wide Web is another
popular
way of
sharing
information on the Internet.

It uses a special language called
HTML , which
stands for


Hypertext Markup Language”

. A
document
on the web can have text, pictures, animations,
videos and music. Hyperlinks
allow
you to move to other
documents
on the same computer or let you travel ar
ound
the world to another computer on the Internet.


If you want to read web pages you need a special kind of programme called a web browser, that can
understand these
documents

.
Common
web browsers are the Internet Explorer, Netscape
Navigator or Firefox
.

There are over 10
billion documents
on the web. Each one of them has a
unique
address called a
URL (Uniform Resource Locator). It looks like this:

People today like to start their web browser and click from one
website
to another to find information
or to see what’s new. This is called
browsing the net

.








Finding Information

The Internet and the World Wide Web have put a world of information
at our
doorstep

. But how can we find what we’re looking for?
Search engines
help us find the
information we need. Most of them use programmes called spiders that visit as many
websites
as
they can and put them into a
catalogue
or
index

.

However

, Internet users must be careful. Just about anyone can put informatio
n on the web. Some
of that information may be very
accurate

, but other information may be completely wrong. So
it’s
up to us
to find out what’s right and what’s wrong.




How we use the Internet

The Internet and the World Wide Web play important
roles
i
n many
areas
of life:



More and more products are sold over the net.
Companies
advertise

their products on
websites
and
customers
can buy
them
online
without going to a shop.



Software can be
downloaded
from
servers

.



News agencies
,
newspapers

and TV stations bring
breaking
news stories to a
worldwide audience

. You can watch

videos ,listen to interviews and look at photos of
major
events whenever you want to.



People buy
fewer
CDs in music stores. More and more songs
are
downloaded
from the Internet and copied to a discman
or an
MP3 player

.



Schools and universities use the
Internet to find information.
Pupils often get their homework over the Internet or send
teachers
essays
and other homework. Pupils and teachers
communicate
with each other by email and in chat
sessions

.



Scientists
all over the world
share
information on
different
kinds of projects and experiments. It is even possible to
make instruments, like
telescopes
or
microscopes
, work
by
remote control

.



The Internet has made travelling easier. You can book
holidays and buy flight tickets on the net.




Major
search engine Google




Dangers on the Internet

The Internet has many good sides but there are also dangers on the
net. Here are some things that you should be
aware
of:



Viruses are small computer programmes that are
created
by
people who want to do
damage
to the Internet. They are
made to make computers slower or, in some
cases
,
erase
important information or even make a computer
crash
. The
Internet has made it easy to send these programmes from
one computer to another. Very often, you get a virus
by
opening a
file
that comes with an email.

You can
protect
yourself by using anti
-
virus programmes.
They warn you if a virus has
reached
your computer or if
something is wrong.

Do not open email
attachments
if you don’t know who sent
them !



User names
a
nd passwords are very important personal
information . When you
browse the web

there are many
websites
where you have to
type

in such information . You
also need a password to read your email.

o

Protect
your passwords from other eyes.

o

Think of passwords th
at are difficult to find out .
Don’t use your phone number or your
date of birth
.



o

Use a combination of numbers and letters

o

Store
your passwords in a safe place and don’t show
them to anybody.



Hackers
are
waiting to take control of your computer .

Use a
firewall
to keep them out.



From time to
time security holes
are
discovered
. Always
download
patches
that give your
operating system
more
protection
.



Log offline
when you don’t need the Internet.



Be careful
when you buy something from online sto
res and
make sure
you are using a safe
connection

. A
closed
lock
at the bottom of your browser shows you that
you are on a safe
website

.







An Internet ABC


Bookmark

the way of
saving
web pages so that you can go back to them
or find them again

Browser

A program me that finds information on the Internet and shows
it on your computer screen

Domain

the first part of a
website’s
address ; it usually begins with
www and ends with .com, .org , .net or other letters that show
which country the
website
is from

download

to copy information from a computer on the Internet to your
own computer

E
-
Mail

electronic
messages
or letters that you send from one
computer to another

FAQ

is a short word for “

Frequently
Asked Questions” ; questions
that many people ask

GIF

a type of computer
file
that pictures on the Internet use

HTML

a computer language that is used to write web pages on the
World Wide Web ; it
stands for

“Hypertext Markup Language”

Hyperlink

a
word or a picture on a web page that will take you to another
page when you click on it

internet

all the computers that are
connected
together on a big
worldwide network
so that they can
communicate
with each
other

JPEG

a type of graphic
file
that is used for pictures and photos on the
Internet

modem

a
device
that you connect to your computer and the telephone
line; it changes
data
that comes from the telephone to
information that you can see on your computer

network

two or more computers

that are
connected
to each other so
that they can
share
information

Offline

if your computer is not
connected
to the Internet

online

a computer that is
connected
to the Internet

website

a place on the Internet where you can find information about
something




Words



accurate
= true and correct



advertise
= to tell people about a product, so that they
can buy it



allow
=let



appear
= you can see it



area
= field



arrive
= get to



attachment
= a file that comes with an email



audience
= people who watch or listen to something



aware
= be careful of



billion
= 1,000 million



board
= group



breaking
= here: an important event becomes known



broken up
=split apart



browse the web
= to
click from one website to another



business
=the buying and selling of goods



came up
= started



case
=situation



catalogue
= a complete list of things



certain
=special



common
= a lot of people use it



communicate
= to exchange information



communication
= the way of sending information



company
= an organisation that makes or sells
something



connect
= to join together



crash
= here : it suddenly stops working



create
= make



customer
= a person who buys something



damage
=the harm done to something



data
= information that is stored on a computer



date of birth
= the day, month and year of your birth



destination
= a place where something or someone is
going to



destination
= a place where something or someone is
going to



device
= a machine



director
y
=catalogue, listing



discover
= to find out about something



document
= a page



doorstep
= very near your home



dot
=point



download
= to move from a computer on the Internet to
your own computer



education
= teaching and learning



entertainment
=films,
television and other performances
that people go to or watch



erase
= to remove information from a computer



essay
= if you write about your ideas on a subject



far apart
= to be far away



few
= not many



file
= information on your computer that you store
under
a special name



firewall
= a system that protects your computer so that
others cannot read data that you have saved or change
programmes



folder
=directory, listing



frequent
= often



from time to time

= sometimes



government
=the people who rule a c
ountry



hacker
= a person who gets into your computer and
changes information that you have saved



however
=

but



immediately
= at once , right away



index
= here: database with a list of names or other
information



it’s up to us
= it’s the work we have to do, it’s our job



lock
= an object that keeps something closed so that you
cannot get in



log offline
= to stop using the Internet



major
= big, important



make sure
=to find out if something is true or see if it
has been done



message
= written information that you send to someone



microscope
= an instrument that makes small things
look larger



MP3 player
= a small machine that can play music that is
downloaded from the web



network
= a group of computers that are connected to
e
ach other and exchange information



news agency
= an organisation that collects news stories
and gives them to newspapers, radio and TV stations



occur
= happen, exist



on their own
=by themselves



online
= if you are connected to the Internet



operating s
ystem
=a system in a computer that helps
all the programs work together



packet
=small part



patch
= a small computer programme that you install to
make your computer safer



popular
= liked by a lot of people



post
= to put a message on the Internet so tha
t people
can read it



protect
=defend, guard



reach
= get to



remote control
=a thing you use to control a TV or a
radio without having to touch it



right order
= in the same way that they started out



role
= part



route
= path, a way from one place to ano
ther



save
= store



scientist
=a person who is trained in science



screen
=computer monitor



search engine
= a computer programme that helps you
find information on the Internet



security holes
=areas into which viruses can get into
your system



separate
=divide



server
= a big computer on a network that controls all
the others



session
= meeting



share
= use together



stands for
= means



store
= save



subject
= thing that you talk about



telescope
= an instrument with which you can see things
in space



to
p level
= highest



type
= write with a keyboard



unique
= there is only one in the whole world



user name
=a special name or word that allows you to
work on a computer or send and get emails



website
= a place on the Internet where you can find
information

about something



whole
= all of



worldwide
= in the whole world