Internet vs Intranet vs Extranet
Computer networks differ from each other depending on their topology. Each type of network has its own characteristics which provide desired level of service to the audience. There are three comprehensive types of networks, Internet, Intranet and extranet. Each network shares same communication technologies. They differ in terms of size, access levels and the nature of users.
Internet is a “Public network” with thousands of computers (servers and clients) interconnected to share information. Clusters of computer networks are interconnected to build the network spanning all over the world. There is no centralized controller to control communication. It relies on network devices and protocols (Ex routing protocols) previously agreed upon. Any user can access Internet through an Internet Service Provider (ISP). Generally, internet is unregulated and uncensored, but there are some countries with restrictions imposed on internet access to their citizen. Although there is no centralized entity to control, ICANN (The Internet Corporation for Assigned names and Numbers) manages Internet Protocol Addresses and Domain Names.
Intranet is a “Private network” with a limited number of computers interconnected and controlled in a defined manner. Intranet is setup and controlled by an organization, to ensure secure and uninterrupted connection between members to exchange information more efficiently. Organization requirements may include sharing latest news updates, management information, organization changes, new policies and procedures etc.
Intranet is much like the Internet, but it is isolated from the external world. Firewalls are used to connect Intranet to the outside world when it has to be connected to Internet. It uses same protocols like TCP/IP. Size of the Intranet depends on the organization requirements. It may span over one building, one area, or one country. In addition, there are many multinational organizations maintain Intranets between countries using dedicated fiber optic connections. Communication efficiency between network devices is high since the bandwidth is fully assigned to a fixed number of users. There are no frequent traffic spikes, channel breakdowns or server offline situations in the Intranet. Intranet may be accessible through the Internet. There are techniques like VPN connection to provide secure connections in such situations.
Extranet is part of an Intranet, which is also categorized as a “Private Network”. It is controlled and managed by an organization, to provide secure access to Intranet from the outside world. Many business organizations need their business partners and customers to connect to Intranet to enhance communication and efficiency. Since the Intranet permits only internal members to gain access, external members (partners and customers) use Extranet to access the network. System administration/management can decide which users should allow through Extranet. Generally, external users are given limited access over the Intranet.
Not only external users, sometimes members of the organization itself who may need to access the network over the Internet can use Extranet.
What is the difference between Internet, Intranet and Extranet?
• When it comes to size of the network, Internet is the largest and consists hundreds of thousands of network devices and interconnections. Intranet size may span from hundreds to several thousands of computers. Extranet comes as a part of Intranet, so it is the smallest.
• Internet is a public network. Intranet and Extranet are private networks.
• Users can access Internet anonymously. Users should have valid username/password to access Intranet and Extranet.
• Generally, Internet is unregulated and uncensored. But Intranet/Extranet is regulated by the organization policies.
• In the nature of users, Internet has unlimited number of anonymous users. Intranet keeps limited number of predefined users who are internal members of the organization. Extranet users are mostly non-organizational users.