What Are Intranets and Extranets in Corporate Portals?

The "Internet," "intranet" and "extranet" all sound alike, and the technologies they represent share some commonalities, but they have specific differences that businesses need to know and understand in order to take advantage of them. We all know what the internet is and access it daily for different purposes. An intranet is a company's secure private local network that is not meant to be accessed by anyone outside the company. An extranet is an intranet that is accessible only to certain designated individuals outside the company, but it is not a public network.

An intranet is a generic term for a private computer network within an organization. An intranet is a local network that uses network technology as a tool to facilitate communication between people or workgroups to improve the data sharing capability and overall knowledge base of an organization's employees. An intranet is used by a company's employees in the course of the workday.​

Intranets use standard network hardware and software technologies such as Ethernet, Wi-Fi, TCP/IP, web browsers and web servers. An organization's intranet may include internet access, but it is firewalled so that its computers cannot be reached directly from outside the company.

Many schools and nonprofit groups have also deployed intranets also, but an intranet is still seen primarily as a corporate productivity tool. A simple intranet for a small business consists of an internal email system and perhaps a message board service. More sophisticated intranets include internal websites and databases containing company news, forms, and personal information.

An extranet is an extension to an intranet that allows controlled access from the outside for specific business or educational purposes. Extranets are extensions to, or segments of, private intranet networks built by businesses for information sharing and e-commerce.

For example, a company that has a satellite office might allow access to the company's intranet from the employees of the satellite location.