Given its capabilities and widespread use, the Internet is a powerful business tool. Companies can communicate efficiently and cost-effectively with employees and potential customers worldwide.

An intranet is a private TCP/IP-based network of computers on an organization's secure local area network (LAN). An intranet typically contains confidential and sensitive company documents. Each intranet is custom-designed to meet an organization's needs. As such, only an organization's employees have access to it. The employees access the intranet using the same Web browser they use to access the Internet (for example, Firefox or Microsoft's Internet Explorer).

An extranet is a special portion of an intranet to which only authorized users may send and receive information or conduct transactions. Think of an extranet as an intranet that allows a company's clients to access it. Extranets can be completely outside a company's network or they can be attached through secure measures.
The Slide Show shows examples of how businesses might use intranets and extranets.