Transcript INTERNET

INTERNET
WHAT IS INTERNET
Internet is an international network of
networks that connects computers worldwide.
It connects universities, research facilities,
governmental organizations allowing them to
access, share and exchange information.
Connecting to internet
To get connected to the internet you need a
communication links between your computer
and a host computer and hardware and
software.
A host computer is a computer that is already
connected to the internet. Access to a host
computer is made available through an
internet service provider (ISP).
WAY TO CONNECT TO INTERNET
DIAL-UP: YOUR COMPUTER DIALS A PHONE
NUMBER TO CONNECT YOU TO YOUR ISP USING
A TELEPHONE LINE.
DEDICATED CONNECTION: THIS MEANS THAT YOU
HAVE A PERMANENT CONNECTION AND ARE
PART OF THE INTERNET AT ALL TIMES. IN MANY
COUNTRIES. TV CABLE COMPANIES INSTALL A
SINGLE CABLE TO PROVIDE CABLE TV, TELEPHONE
AND INTERNET SERVICES TO CUSTOMERS.
TRANSMISSION CONTROL
PROTOCOL/INTERNET PROTOCOL
TCP/IP IS A SET OF PROTOCOLS USED TO
TRANSFER DATA FROM ONE COMPUTER TO
ANOTHER OVER THE INTERNET.A PROTOCOL IS
A SET OF RULES THAT DEFINES HOW
COMPUTERS INTERACT OR COMMUNICATE
WITH EACH OTHER.
WORLD WIDE WEB
The Internet is a world-wide web that has
grown and evolved from an experimental
network (ARPANet) created by the US military
back in the 1960s. Over the years, as more
and more computers and networks have
connected to this network, it has grown into
the Internet that we know.
BROWSERS
A web browser is a software that lets you access
the information available on the web. Popular
web browsers include:
Microsoft internet explorer.
Mozilla firefox.
Internet addresses
Each computer on the internet has a unique
address that identifies it. This unique address
is a number called the IP address ( internet
protocol address)
Web addresses or URLs
The IP addresses used by software are difficult
for humans to remember so URLs (uniform
resource locators) or web addresses are used
instead. Every web address is unique and is
constructed like this.
Type of resource
It identifies the type of resource. There are
several different types for example http://
identifies a web page and mailto:// identifies
an e-mail address.
Host computer
It is the name of the host computer or web
server. This must be unique within the
domain.
Domain
It identifies the type of organisation that owns
the website. There are several different types
of domains, for example.
.com identifies an international commercial
organisation.
.co.uk identifies a UK- based commercial
organisation
.ac.uk identifies a UK based university or other
academic institution.
.org.uk identifies a UK based non- commercial
organisation.
e.g.
http:// yahoo.com
What can you do on internet
• View web pages on the WWW (World-Wide
Web)
• Sending and receiving e-mail messages
• Sharing files
• Communicating using voice (VOIP)
and video (video-conferencing)
• Playing multi-player games
• Listening to streamed music or
watching streamed video
Intranet
• An intranet is the name given to a private
network that provides similar services to The
Internet: e-mail, messaging, web pages, etc.
However, these services are only for the users of
the intranet – they are private, not public (unlike
Internet services which are generally public).
Businesses and other organisations often have
intranets for use by their employees.
Typical uses of an intranet would be:
Viewing internal web pages (e.g. company calendars,
etc.)
• Internal e-mail and instant-messaging between
workers
• Sharing of internal documents
E-Mail
E-mail is a system that allows messages to
be sent and received by computers. E-mail is
the most common form of electronic
communication.
E-mail messages are text-based, but other types
of file can also be sent as ‘attachments’.
E-mails that are received wait in a
user's inbox until the user is ready to read them.
(Unlike a telephone call, the user is free to ignore
e-mails until they have time to deal with them.)
Sending an e-mail
An e-mail message usually has the following
parts:
To
The address(es) of the person who the
message is for
Subject
A short sentance describing what the
message is about
Message
The text of the message. This can be as long
as you like
An e-mail may also include the following parts:
CC
The address(es) of people to copy the e-mail
to (Carbon Copy)
BCC
The address(es) of people to copy the e-mail to
without anyone else knowing (Blind Carbon
Copy)
Attachments
Files linked to the message (images,
documents, etc.)
For an e-mail message to be sent and received,
the following must be in place:
E-mail server: this is a computer on the internet
that receives incoming messages and delivers
outgoing messages. It allocates a certain
amount of storage to hold mail for registered
users.
E-mail client: this is a program that enables you
to read and compose e-mail messages and to
send and access e-mail from the server, e.g.
Microsoft outlook.
Storing an e-mail
Do it yourself.