An extranet is a controlled private network allowing customers, partners, vendors, suppliers and other businesses to gain information, typically about a specific company or educational institution, and do so without granting access to the organization's entire network. An extranet is often a private part of a website. It is restricted to select users through user IDs, passwords and other authentication mechanisms on a login page.
An extranet may be viewed as an intranet mapped onto the public Internet or onto some other private network.
Advantages of extranets include:
- The ability to exchange large volumes of data using electronic data interchange
- Sharing product data or catalogs with business partners
- Joint company collaboration and training
- Sharing services such as online banking applications among affiliated banks
Disadvantages are expensive implementation and maintenance if hosted internally and the potential for compromised sensitive or proprietary information. Alternately, it may be hosted by an application service provider.