Difference Between Internet,Intranet and Extranet.

Internet

An electronic network of computers that includes nearly every university, government, and research facility in the world. Also included are many commercial sites. It started with four interconnected computers in 1969 and was known as ARPAnet.

A network of computer networks which operates world-wide using a common set of communications protocols.

The vast collection of inter-connected networks across the world that all use the TCP/IP protocols.

A global network connecting millions of computers.

A worldwide network of computer networks.

It is an interconnection of large and small networks around the globe. The Internet began in 1962 as a resilient computer network for the US military and over time has grown into a global communication tool of more than 12,000 computer networks that share a common addressing scheme.


Intranet


An internal use, private network inside an organisation that uses the same kind of software which would also be found on the Internet.

Inter-connected network within one organization that uses Web technologies for the sharing of information internally, not world wide. Such information might include organization policies and procedures, announcements, or information about new products.

An intranet is a restricted-access network that works like the Web, but isn't on it. Usually owned and managed by a company, an intranet enables a company to share its resources with its employees without confidential information being made available to everyone with Internet access.

A network based on TCP/IP protocols (an internet) belonging to an organization, usually a corporation, accessible only by the organization's members, employees, or others with authorization. An intranet's Web sites look and act just like any other Web sites, but the firewall surrounding an intranet fends off unauthorized access. Like the Internet itself, intranets are used to share information.


Extranet


An extranet is a private network that uses the Internet protocols and the public telecommunication system to securely share part of a business's information or operations with suppliers, vendors, partners, customers, or other businesses. An extranet can be viewed as part of a company's intranet that is extended to users outside the company. An extranet requires security and privacy.

A new buzzword that refers to an intranet that is partially accessible to authorized outsiders. Whereas an intranet resides behind a firewall and is accessible only to people who 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 which parts of the extranet you can view.