Intranets and Extranets

Intranets and extranets are special types of networks that use the same technology as the World Wide Web. Data is stored on servers and is communicated via the TCP/IP protocol. If the Internet is the global village, then intranets and extranets are private, gated communities within that village. As an authorized user, you can access the intranet or extranet through your regular browser, but if you aren't an authorized user, you won't be able to get past the gate.

Intranets are commonly used for internal communications in corporations or educational institutions. Strictly speaking, an intranet does not allow any access from the outside Internet. Only computers connected to the internal network can connect to the intranet.

Once you allow authorized external users to connect to an intranet, it becomes an extranet. An extranet is still restricted, but allows access by certain networks, computers, or individual users.

Intranets and extranets are protected by firewalls. A firewall prevents unauthorized access to the information on the server by blocking requests from computers outside the immediate network or by permitting access from only specific computers. Firewalls can be a combination of hardware and software or software only.

Are you using an extranet?

Some web sites really cross the line into extranet functionality. For example, if you check your credit card or bank account balances online, you are really logging-on to an extranet. Your private information is secure, because you are required to log-on to the web site with a secure account user name and password. You (the customer) have access to information that is not available to the general public.