Email and Internet - Milestone International College

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26 Οκτ 2013 (πριν από 4 χρόνια και 15 μέρες)

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1



Emai
l

and Internet


History of Internet

The US department of defense laid the foun
dation of the internet roughly 4
0 years ago with a
network called ARPNET (Advance Research Projects Agency Net). During the 1970’s work an
ARPANET consisted of connecting
the various networks and developing the necessary internet
software. During the early 1980’s the network became known as the internet and it was during
that period that business firms began using it but the general public started using internet after
the d
evelopment of world wide web in the early 1990’s. In 1993 there were only 130 websites all
over the world now there are millions of websites all over the world.

Q1.
What is Internet?
What are the uses and misuses of internet?

Internet is not just like one
network, it is a coordinated union of a multitude of networks all over
the world or we can say internet is the world largest computer networking, the network of
networks. Internet is global LAN where millions of comput
ers are connected to each other,

any
c
omputer user on internet can contact another user on the internet anywhere in the world, very
much like telephone user communicates with another user anywhere in the world. Internet is an
information superhighway and has seemingly compressed the world into

a cyber colony.
It
Internet is a global collection of computers that are connected to each other with network cables,
telephone lines, satellite etc.
Some computers (servers) on the internet store documents, sound
files, video clips, program files, electr
onic shopping centers, animations, pictures and other
information. All these resources are available to all the computers connected to the internet.
Internet is available to anyone who wants to use it. A majority of internet users are college
students, bus
inessmen, professionals etc and accessing internet has become a way of life.

Uses of internet

Internet is used in many ways. The main use of internet is sharing and getting information. The
internet

can be used for academic as well as business purposes. Internet became the part of our
life;
today we are as dependent on internet as we are dependent on electricity, water and other
daily
needs.

The important thing to realize is that the internet permits

almost anything but our
imagination is the only limit.

The main uses of internet are:
-

a)

Communication medium

b)

Information sharing

c)

Entertainment

d)

Online services


2


a)

Communication medium:
-
The internet was designed to share information from one
location to others

through computers. Still innovation and advancements are going on to
make the internet faster, more reliable, easier and cheaper communication medium.

b)


Information sharing:

-

Information sharing is one of the biggest advantages of the
internet. The search

engine like Google, yahoo and others find the resource site and
display to the users. We can find almost any type of data on any kind of subject in
internet.

c)

Entertainment
:
-

Entertainment is another popular reason why people prefer to surf the
internet.
Downloading games, online playing, visiting chat rooms, watching movies are
some of the most entertaining thing done by user on the internet. There are numerous
games that may be downloaded from the internet freely. The industry of online games has
dramati
cally increasing. Chat rooms are popular because users can meet old and new
friends.

d)

Online services:

-

Many services are provided on the internet such as e
-
commerce,
online banking, job searching, tickets reservation for bus, train and aeroplane, tickets
reservation for movies on cinema hall, hotel reservation, online jobs etc. These services
are not available off line hence it is called online services.

Electronic commerce is the
concept used for any type of commercial transaction over the internet with t
he help of e
-
money.

Misuses of internet

Misuses of internet are:
-

a)

Theft of information

b)

Spamming

c)

Virus threat

d)

Pornography


a)

Theft of information:
-

Every computer on the web is connected to others. Some people

(hackers)

can access our computer to misuse our personal and crucial information.

These
information may be our name, bank account number, ATM card number and many
others.

b)

Spamming
:

-

Spamming refers to sending automatic emails in bulk without any purpose
and needle
ssly
obstructs

the entire system. Nowadays these emails are used for the illegal
advertisement of the product or websites.

c)

Virus threat
:

-

Virus is nothing but a program which disrupts the normal functioning of
our computer system. Computers attached to in
ternet are more affected with virus
attacks
which

can crash the whole hard disk, erase files and folders and convert files to
unreadable format.

d)

Pornography
:
-
Pornography

sites are the biggest threats to the teenagers. There are
thousands of pornographic si
te on the internet that can easily found and can be accessed
with the absence of
guide. These

can disturb their
mind and

motivate them to do a crime
which can spoil their life.


3



Q2.
What is Email? What are the advantages and uses of email?

Electronic mail
, commonly called
email

or
e
-
mail
, is a method of exchanging
digital

messages
from an author to one or more recipients. Modern email operates across the
Internet

or other
computer networks
.

Email is a electronic mail

for receiving, sending, and storing electronic
messages.

Email

has gained popularity with the spread of the Internet. In many cases,
email

has
become the preferred method of communication.

The email system are based on store and forward model in which email server computer system
accept, forward, deliver and st
ore messages on behalf of users to send and receive email
messages. Email consists of two parts, the message header and the message body. The header
contains the information such as one or more receivers address,
sender address, data, content
length etc. T
he body part of the email contains the actual message the sender is sending to the
receiver.


It is one of the most frequently used features of the internet. Many people sigh
up for internet service just so that they can send an
d receive e
-
mail message. The internet is now
the world’s largest electronic mail system. More than 30 million people are directly connected to
the internet and can send and receive electronic mail.


Electronic mail has many adv
antages:



Fast:

Most system can relay our message to the recipient in a matter of minutes or
seconds. Many system let us check to see whether the recipient has accessed our message
or not



Easy:
-

When we open our email box we see a list of the message we ha
ve received, first
we read the message and then decide how to respond. We can reply to the message if we
like, or just delete if it requires no reply. We can save it or print it. We can even forward
the message to the other



Fun:
-

International electronic m
ail system enable us to find ‘pen pals’ all over the world



Cheap:
-

We can send messages to others through email around the world cheaply in
comparison to the charge we are paying for telephone service.



Flexible:
-

We can send a message to more than one person if we like.


Uses of Email




E
mail allows individuals and groups to communicate with one another.



Group of people can work on the same topic through email and generate one common
document together.



Through emai
l we can stay in touch with our family, relatives and friend who are away
from us.



It is the convenient way of sending job application, sending valuable documents,
important images and videos.



The use of email is essential when communicating in today's
business

culture
.
Businesses

of all sizes, locations and types can effectively use email for multiple purpose
s. It is the
most efficient way to communicate with management, colleagues, clients and vendors.



Email is used when colleagues of the same or different departments need to send and
receive information about projects

4




Clients and vendors use email to order p
roducts and services



Employees can receive dates and times of meetings, conferences, and mandatory training
sessions via email.




Q3.
What are the different types of email accounts? Explain


Email is one of the most used features of t
he web. With this tec
hnology we

can not only send
text messages but also digital files such as images, audio, video etc. attached with the email
message.
The different type of email accounts are as follows:
-


POP email account:
-

This type of email account requires a client application installed in the users computers. The user
has to get the service from the email service provider for free or by paying some amount. The
user then gets
user id

and password along with the POP mail se
rver configuration required to
setup the email client. The popular email clients are Microsoft Outlook, Opera Mail etc. To send
the mail user composes the mail using the email client and post the mail to the email server. The
email server then sends the ma
il to the destination address.


Web based email accounts
:
-

Web based email accounts can be accessed using a web browser
(yes, the same program that we
use for surf
ing

the web)
we

can compose, reply, send, for
ward and organize email.

To gain access to our
account, we

use a web browser to visit the
home page

of

the email service
and enter our

login details (username and password). All
our

email

messages and address book
(contact lists) are stored on web servers owned by the respective companies.
We

need an active
internet connection to log on to
ou
r account and
check our emails
.

For instance, the
Hotmail sign
in page

is located at www.hotmail.com and to login at
ou
r Hotmail account
we

need to enter
ou
r
full email address and
ou
r password.


Email
accounts provided by the ISP
:
-

ISPs

generally provide an email account for free with the internet connection. If
we

didn't
get
one from
ou
r ISP,
we

should seriously consider shifting to another provider. Anyway, the main
advantage of using an email account provided by the ISP is the support
we

receive
-

we

can
either call the ISP or refer the extended documentation (usually) p
rovided in their manual. ISPs
know that many users would be new to the web and so have helpful and patient staff to help
troubleshoot problems. This is in direct contrast to web based email service providers such as
Hotmail, Gmail or Yahoo! Mail where, unl
ess
we

take the paid version, the support is sadly
missing. However, there is one major drawback in having
ou
r ISP account as
ou
r primary email
address for online correspondence. If
we

change
ou
r service provider or shift to a new location
where
ou
r old IS
P has no service,
we

might lose the email address; else
we

have to keep paying
for it.


Web site email accounts
:
-

Do
we

own a web site? Depending on
ou
r hosting package,
we

can
create email accounts on the
web site

for
ou
rselves

or
ou
r staff. Most web hosting companies let
we

access
emails through a
web based interface or download the messages using email programs such as
Outlook Express
,
Windows Mail
,
Windows Live Mail
, Thunderbird, Apple Mail etc.



5


Email accounts from institut
ions, schools, colleges etc:
-

We

can even get
an

email account from
ou
r institution or school.
We
, typically
, need to contact
the IT department

that provides the email id and password required for the email service

.This
type
of
email

account

is not recommended to be
used
as

our primary email account
. It's good for
internal purposes
b
ecause
email account is unus
able

once
we

leave the institution or the school.


Email account from
ou
r company
:
-

If
we

work in a medium
-
sized or a large company they would probably have their own email
servers. Generally,
we

get
ou
r own email address

a few days after joining the company. This
would be
ou
r business email ID
.I
t is better to keep this
type of
email account away from
personal correspondence.




Q4. Define protocol. What are the different types of protocol?


Protocol

Protocols are the rules of transmission.
In
other words protocol is a set of rules which is used by
computer to communicate with each other across the
network. As

we know that for a
transmission of data/information to be successful, each of the devices/computers attached to both
ends must speak the
same set of languages, must have same set of devices and same types of
software. But practically it is impossible in this distributed world. To overcome this limitation,
certain set of rules which are common and acceptable by both the parties are developed

which
play a role of interpreter between the sender and the receiver, which is known as protocols.


The different types of protocols are as follows:
-

a)

IP ( Internet Protocol)

b)

TCP ( Transmission Control Protocol)

c)

UDP (User Datagram Protocol)
\

d)

HTTP( Hyperte
xt Transfer Protocol)

e)

FTP( File Transfer Protocol)

f)

SMTP ( Simple Mail Transfer Protocol)

g)

Telnet( Terminal Network)

h)

POP ( Post Office Protocol)



a)

IP (Internet Protocol):
-

It is a protocol defined in the internet layer of the TCP/IP
protocol suite. The main
task of IP is the best effort delivery of the
packets.

It

is
responsible for moving packet of data from node to node. IP forwards each packet based
on a four byte destination address (the IP number). The Internet authorities assign ranges
of numbers to different organizations. The organizations assign groups of
their numbers
to departments. IP operates on gateway machines that move data from department to
organization to region and then around the world.


b)

TCP (Transmission Control Protocol)
:
-

It is one of the main protocol of the internet
protocol suite. The fu
nction of TCP is the reliable, ordered delivery of stream of bytes
from a program on one computer to another computer.

It

is responsible for verifying the
correct delivery of data from client to server. Data can be lost in the intermediate
network. It adds

support to detect errors or lost data and to trigger retransmission until the
data is correctly and completely received.


6


c)

UDP (User Datagram Protocol):
-
It is one of the core members of the
Internet Protocol
Suite
,

the set of network protocols used for the
Internet
.

It

is a simple
OSI transport layer

protocol for client/server network applications based on
Internet Protocol (IP)
.

UDP is
the main alternative to
TCP

and one of the oldest network protocols in existence,
introduced in 1980.

It

is often used in videoconferencing applications or computer games
specially tuned for real
-
time performance.

It is useful in applications where reliability is
not a major concern but speed is a major concern.

d)

HTTP (Hypertext Transfer Protocol):
-

It is one

of the popular application layer
protocol which
specifies

the rules for the interlinked documents called hypertext
documents which contain text images, videos and other multimedia contents.

HTTP is the
foundation of data communication for the
World Wide Web
.
The standards development
of HTTP has been coordinated by the
Internet Engineering Task Force

(IETF) and the
World Wide Web Consortium

(
W3C).

The HTTP protocol is designed to permit
intermediate network elements to improve or enable communications between clients and
servers.

e)

FTP (File Transfer Prot
ocol):
-

It is a reliable and secure file transfer protocol which
requires user to log into the system before file transfer. It helps us to upload the files to
the websites which we are maintaining. Transferring a file require two participants


FTP
client
program and FTP server program. FTP client program run in our computer and
FTP server program run on the server computer.

f)

Telnet (Terminal Network):
-
Telnet is the internet tool or protocol that let us travel from
our own workstation out into cyberspace to
land on another computer. Telnet is useful for
the remote administration of internet hosts over the internet.

g)

SMTP (Simple Mail Transfer Protocol):
-

It is specified for outgoing mail from one
email server to another. The SMTP is extended to send other type of information such as
text, picture,
and video

and other multimedia program and data files.

h)

POP (Post Office Protocol):
-

It is used to receive email from a remote mail server. It is
designed to support offline mail processing. Using POP mail is delivered to a central
server and the user uses a mail program like Eudora, outlook, Netscape Messenger etc
that connects to the se
rver and downloads all of the new emails to the users own
computer.



Q5. Define the following term


Web
Browser
:
-

Software that lets a user to view HTML documents and access files and
software related to those documents. Originally developed to allow use
rs to view or browse
documents on the World Wide Web or internet. Most popular web
browsers are

Microsoft
Explorer, Mozilla Firefox etc.


Web page:
-

Web page is a document typically written in plain text with formatting instructions
of hypertext markup la
nguage (HTML, XHTML). Example:
-
www. Educationsansar.com


Website:
-

Website is a collection of related WebPages. A group of related HTML documents
and associated files, scripts and databases that is served up by an HTTP server on the World
Wide Web is web
site.



7


Web server
:
-

a computer system and its software that is built to serve multiple requests of
clients to access web pages is called web server. Example
:
-

Google web server.


DNS (Domain Name System):
-

DNS is a hierarchical system by which hosts on
the internet
have both domain name address and IP address. The DNS server plays critical roles for
converting domain names to it corresponding addresses


URL (Uniform Resource Locator):
-

A URL is the standard address used to find a page, web
server or othe
r device on the web or the internet. A typical address or URL is
http://www.undp.org.np

The first part of the address specifies the protocol used for connection to the server, http
stands for hypertext transfer protoc
ol, which is used for websites.

Domain Names:
-

Domain name is a string of identifiers separated by full
-
stop ( called dot when
we are reading out an address. The domain name of the servers identifies the type of organization
and often the country in which

the server is located.


Example:
-



.com
-

commercial organizations


.edu
-
Educational organizations


.gov
-

US governmental organizations


. np


representing
nepal


World Wide Web (WWW):
-

The World Wide Web is one of the newest and most popular
hypertext based internet tools. It allows users to access and display documents and graphics
stored on any server on the internet. In 1989, Tim Burners
-
Lee, a computer scientist designed
WWW as a to
ol to help an international group of physicists to exchange findings and
information related to their research.


Home page:

-

H
ome page is an electronic description of the company and its products and
services, similar to a catalog or a brochure. Just as catalogs should be attractive and grab the
interest of customers, the homepage should also be attractive and encourage the user
to further
explore the company and its products. It can cost from Rs 5000 to 10000 for each website but for
interactive homepages (where the user and the system can interact) the cost can be higher.


Q6.
What are the advantage
s

and disadvantage
s

of POP 3 e
mails?

Advantages:
-

1) No need to connect internet to read old emails and to compose new one.

2) It secures emails because emails are store in the local computer not in the remote
server.

3) Advertise and spam mail are automatically blocked by the softwar
e

4) The quantity of the emails and size are not limited, any number of emails can be store
on local computers hard disk.


Disadvantage:
-

1)

POP3 email server are not free we need to buy account.

2)

Every email store in the local computer disk
spaces,

accidental

deletion and managing of
all email should take care by self.

3)

POP3 emails can be viewed from one computer only not suitable for those people who
access emails from different computers.

8


4)

During the system shifting or format all the emails should care by self
.

5)

We need third party software to access emails from server.



Q7.
What are the Advantage
s

and disadvantage
s

of Web based mail are:
-

Advantage:
-


1) No need of third party software to view it simple web browser can access it.

2) Most of the web mail
services are free on the web

4) The email inbox can be accessed from all around the globe having internet connection
and computer.

5) It can be accessed from the different computer platform i.e. can be accessed through
Window, Mac, Linux etc

Disadvantage:
-

1)

Webmail are slow to access because every email should be accessed and download from
the server to view it.

2)

Webmail do not have off
-
line messaging services, we need internet connection.

3)

Webmail consists of large number of advertise and spam emails.

4)

Size on

the web mail server for one user account is limited, for large spaces we need to
buy spaces.


Q8. Write Short notes on TCP/IP

TCP/IP:
-

TCP/IP is the communication protocol for the internet.
TCP/IP (Transmission Control
Protocol/Internet Protocol) is a set
of protocols enabling computers to talk to each other over
networks. TCP/IP only applies where there is a network. Each computer on a network that wants
to use TCP/IP has an
IP

address
, for example, 192.168.123.1.

TCP and IP were developed by a
Department
of Defense (DOD) research project to connect a number different networks designed
by different vendors into a network of networks (the "Internet"). It was initially successful
because it delivered a few basic services that everyone needs (file transfer, el
ectronic mail,
remote logon) across a very large number of client and server systems.

Several computers in a
small department can use TCP/IP (along with other protocols) on a single LAN.