Intranet is a network which is only available inside an organization or a company. It can be accessed by all the computers that are operated inside the company's premises and is not connected to the Internet. The purpose is to keep information contained inside the organization and prevent leak of information due to employee errors or hacking attempts.
Extranet is an extension of intranet to some entities outside the organization or a company. For example if a company allows its customers to connect to the company intranet, then it will form an extranet, which is composed of computers inside the company and outside the company but still is separated from the regular internet. We can differentiate all three network on basic of their access for Internet we can say it's public-ally accessible any one can long into the network.
For intranet is for a particular company for extra net we can say particular a department of the company 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.
Intranet::
An internal use, private network inside an organization that uses the same kind of