THE INTERNET
Internet
is a collection of computers all linked together
to share information worldwide. It is one of the largest
networks that link trillions of computers all over the world. You can access this network via
communication devices and media such as modems, cable, telephone lines and
satellite.
It is a large set of computer
network that communicate with each other.
It enables companies, organisations, individuals, schools
and government to share information across the world.
The internet offers
many conveniences at your fingertips. You can send messages to others, meet new friends,
bank, invest, shop,
fill prescriptions, file taxes, take online courses, play games, listen to music or
watch a movie on the internet. The advantage of the internet is that you can
use it from a computer anywhere in the world.
Success today in the business
world requires knowledge of the internet. Without it, you are missing
out on a tremendous source
for goods, services, information and, communication.
Here are some of the
things one can do on the
internet.
1. Banking called E-banking 0r Internet Banking
2. Invest
3. Shop for goods
and services
4. Watch movies
5. Download and listen
to music
6. Access Educational material
e.g. www.mrcomputerclass.blogspot.com
7. Access source of entertainment and leisure, such as online
games, magazines or vacation
planning guide
8. Access other computer
and exchange files, share
and edit documents with others in real-time
9. Provide information, photographs or audio or video clips
History of the Internet
The history
of the internet begins with the following:
1. ARPANET:
The US defense
department created a project called
Advanced Research Project
Agency (ARPA) in the late 1960s, which
was to work as a network that would allow
scientist and military
personnel to exchange information in war scenario without disruption in
communications.
The network was connected in a way which ensured
that if one section of the network
was damaged, the remaining computer
on the network would still
be able to communicate
with each other. This network was called ARPANET. By 1984, ARPANET had more
than 1,000 individual computers linked as hosts.
2. NSFNET:
In 1986, the national science
foundation (NSF) connected its huge network
of five supercomputer centre called NSFNET,
to ARPANET. They used the technology developed for ARPANET to allow universities and schools to connect to each
other.
By 1987, NSFNET could no longer handle the
amount of information that was being transferred. The national science
foundation improved the network to allow more
information to be transferred. This configuration of this complex
network came to be known
as the internet. Most of the people
accessing the internet
until the late 1980s were scientist and researchers.
In the early 1990s,
many companies started to offer access to home users. This allows anyone with a modem
and a computer to access the internet.
3. WORLD WIDE WEB:
The World Wide Web was created in the early
1990s by European
organization for nuclear
research. The goal of WWW was also to allow
researchers to work together on projects
and to make project information easily accessible.
The first publicly
accessible website was created in 1991. By the mid-1990s, over 30 million
people had access
to the internet. Reach this huge market,
most big companies created their own sites on the World Wide Web or provide
information about their products. Now there are thousands of companies on the
web.
How the Internet
Works
On the internet, data and
information are transferred worldwide through
the servers and clients (which are computers) connected to the internet.
The computers which are responsible for the
management of resources i.e. program and data on a network, by providing a
centralized storage area, is called a SERVER. The computer which has access to the contents
of the storage area on the server
is called the CLIENT. On the internet, a client which
can access file and services
on a number of servers called a Host computer. Your
computer is a Host computer.
The inner structure of the internet
resembles a transportation system. In the transportation system,
the maximum load of traffic
is concentrated on the highways, which are linked to the major cities. Similarly, on
the internet, there are certain main communication lines which carry the
maximum load of traffic. These lines are collectively called the INTERNET BACKBONE.
The internet is a packet-oriented network. It means that the data you transfer is divided into packets. So, what happens when you transfer data
across the internet various networks?
The networks are linked by special computers, called ROUTERS. A router checks
where your packet
data goes and decides in which direction to send it. Of course,
not every router is linked with every other router,
they just decide on the direction your data takes. The internet knows where
your data is going, as every destination has an address called an Internet Protocol (IP) address. The data transferred
with IP is divided into packets. This is handled by another protocol, the
transmission control protocol (TCP).
Features of Internet
1.
WEBSITE
A website is a collection of web pages.
Most websites have a home page as their starting
point, which frequently has a table
of contents for the site.
Users need a web browser and a connection to access a
website.
2.
WEB PAGE
A web page is an electronic document
on the World Wide Web. It may contain text,
pictures, sounds, graphics
or video. Every
webpage is identified by a unique
address or URL (Uniform Resource Location). That
allows you to find it among the millions of other documents on the world wide
web. Examples include www.google.com, www.yahoo.com, etc. Usually, a web page contains links to other pages as well.
3.
HYPERLINKS
This connects webpages on the internet. A
hyperlink can connect one section of a webpage to another section of the same
webpage. It can also be used to connect a document to another document
on the same website, or to a document on another website
anywhere in the world. You can easily
identify a text hyperlink on a web page because it appears underlined and in
colour.
4.
HOME PAGE
The home page is the first page retrieved when accessing a website. It serves as a table
of contents for the rest of the pages on the site and offers
links to other
websites. For example, a
company’s welcome page typically includes the company logo, a brief description
and links to the additional documents available on that site.
5.
UNIFORM RESOURCE LOCATOR
(URL)
The uniform resource
locator is the address
that defines the router to a file on
the web. URLs are
typed into the browser to access
web pages for example www.google.com.
6.
WEB SERVER
A web server
is a computer on the internet
that stores web pages.
A web page is available for other people to view when it is stored
in the webserver.
7.
WEB BROWSER
A web browser
is a software program that allows you to access
and view web pages. The web browser
software is built
on the hyperlinks, which allows
users to point
and click with a mouse in
order to jump from one document to another in whatever order they are desire.
Internet
Environment: Characteristics Features, Uses
Today, we will be discussing the internet environment.
INTERNET ENVIRONMENT
An internet is a logical collection of
networks supported by gateways, routers, bridges, hosts, and various layers of protocols.
An internet permits different physical networks to function as a
single, large, virtual
network, and permits dissimilar computers to
communicate with each other, regardless of their physical connections.
Characteristic Features
1. Client: A client is a computer
or process that requests services
on the network. A server
is a computer or process
that responds to a request
for service from a client.
A user accesses a service, which allows the use of data or some other
resource.
2. Host: A host is a computer,
connected to a network, that provides an access point to
that network. A host
can be a client, a server,
or a client and server simultaneously.
In a communication network, computers are both the sources and destinations of the packets.
The local host is the computer to which a user’s terminal
is directly connected without the use of an internet.
A foreign host is any machine on a network
that can be interconnected. A remote host is any machine on a network
that requires a physical link to interconnect with the network.
3. Network: A network is the combination of two or more nodes
and the connecting branches among them.
A physical network
is the hardware that makes
up a network. A logical
network is the abstract organization overlaid on one or more physical networks.
An internet is an example of a logical network.
4. Packet: Packet refers to the unit or block
of data of one transaction between a host and its network. A packet usually
contains a network
header, at least
one high-level protocol
header, and data blocks.
Generally, the format
of the data blocks does not affect
how packets are handled. Packets
are the exchange
medium used at the internetwork layer to send and receive
data through the network.
5.
Port:
A port is an end point for communication between
applications, generally referring to a logical
connection. A port provides queues
for sending and receiving data.
Each port has a port number
for identification. When the port number is combined with an internet address,
a socket address results.
6. Protocol:
Protocol
refers to a set
of rules for achieving communication on a network.
Uses of the Internet
1.
Communication
2.
Shopping
3.
E-learning
4.
Research
5.
Entertainment
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