introduction to internet

1. Key difference:The Internet is the massive global system that
connects computer networks around the world together. Millions of
private, public, academic, business, and government networks
worldwide connect with each other over the internet to share massive
amounts of information, resources and services. Intranet is an
internal network. It is used by companies to connect their computers
on a network. Only the members of the corporation with authorized
access may log on and access the network and the data on the
network. Extranet, on the other hand, is an internal network that can
be accessed externally. The extranet can be thought as an extension
of the company’s intranet. People from outside the company can
have a limited access to the company’s internal network for business
or education related purposes.
The Internet is the massive global systemthat connects computer
netw orks around the world together. Millions of private, public, academic, business, and government netw orks worldwide
connect w ith each other over the internet to share massive amounts of information, resources and services. Internet is w hat we
use to access web pages, send e-mails, listen to music or w atch videos online. It hosts an extensive range of information, one
that w e generally take for granted today.
The Internet uses the standard Internet protocolsuite (TCP/IP) to allow us to connect to the net. It has numerous information
resources and services, such as the w eb pages of the World Wide Web (WWW), games, videos, images, e-mail, social
netw orking, etc. It has even spaw ned new servicessuch as Voice overInternet Protocol (VoIP) and Internet Protocol Television
(IPTV). The Internet is currently being used by billions of people w orldwide.
The Internet carries information fromall streams; traditional, such as new spaper, bookand other print publishing; and modern
such as blogging and w eb feeds. It also enabled new forms of human interactions through, instant messaging, e-mail, Internet
forums, and social netw orking. It has gained so much popularity that in fact almost all forms of business communication as w ell
as personalhappens online through e-mail, instant messaging and social netw orking. With phone calls and text messaging
(SMS) coming is second.

2. Intranet, on the other hand, is an internal netw ork. It is used by
companies to connect their computers on a netw ork. Webopedia defines intranet as “a netw orkbased on TCP/IP protocols (an
internet) belonging to an organization, usually a corporation, accessible only by the organization's members, employees, or
others w ith authorization. An intranet's Web sites look and act just like any other Web sites, but the firew allsurrounding an
intranet fends off unauthorized access.”
The intranet is based on TCP/IP protocols, how ever, it is inaccessible fromthe outside. Only the members of the corporation
w ith authorized accessmay log on and access the networkand the data on the netw ork. Like all netw orks, the Intranet is
mainly used to share data, information, resources, company programs, software applications, as wellas facilitate
communication betw een people or w orkgroups within the company. Intranet improves the data sharing capability and overall
know ledge base of the company’s employees.
While, anyone can setup an intranet; it is mainly used by corporations as it is a secure netw orkand is much less expensive to
build and manage than private netw orksbased on proprietary protocols. In fact, Intranets are considered to be one of the
fastest-growing segments of the Internet.
Extranet is basically an internal netw orkthat can be accessed
externally. The extranet can be thought as an extension of the company’s intranet. People fromoutside the company can have
a limited access to the company’s internalnetw orkfor businessor education related purposes. The access may be granted to
the organization’s partners, vendors, suppliers, current and potentialcustomers, etc.
Webopedia defines extranet as “a buzzword that refersto an intranet that is partially accessible to authorized outsiders.
Whereas an intranet resides behind a firew alland is accessible only to people w ho are members of the same company or
organization, an extranet provides various levels of accessibility to outsiders. You can access an extranet only if you have a
valid username and password, and your identity determines w hich parts of the extranet you can view.”
Webopedia also states that the extranets are becoming a very popular means for business partnersto exchange information.
How ever, the extranets require security and privacy, so that the information on the netw orkis not w rongly accessed or misused
by externalparties. In order to protect the netw ork, the extranets can incorporate firewallservermanagement, the issuance and

3. use of digital certificates or similar means of user authentication, encryption of messages, and the use of virtual private
netw orks (VPNs) that tunnel through the public netw ork.
SearchEnterpriseWANlists some of the uses of the extranet:
 Exchange large volumes of data using Electronic Data Interchange (EDI)
 Share product catalogs exclusively with wholesalers or those "in the trade"
 Collaborate w ith other companies on joint development efforts
 Jointly develop and use training programs w ith other companies
 Provide or access services provided by one company to a group of other companies, such as an online banking
application managed by one company on behalf of affiliated banks
 Share new s of common interest exclusively with partner companies
The main difference between the Internet, an intranet and the extranet is that the Internet is open to all, w hereas the intranet is
a limited netw orkand is only open to those w ith appropriate access. Intranet is the netw orkthat is limited for use on the
organizations computers, w hereas the extranet is an extension of the company’s intranet. The extranet makes available some
of the information of the intranet to people not directly connected to the intranet. The Internet is open to all and everyone has
equal and complete access to it. Whereas, the intranet can be accesses by the organization’s staff and the extranet provides
limited access and to a limited group of people outside of the organization.