Internets and Intranets
The separation of terms internet/intranet is used to distinguish between applications that use the Internet (note the capital ‘I”) and those that do not. It is also useful to distinguish between an internet and the Internet.
Internet is a generic term for a set of computer networks connected with routers. The Internet is the biggest example of an internet, and consists of backbone networks (e.g., ARPAnet and NSFNet), mid-level networks, and stub-networks that use specific communication protocols (e.g., TCP/IP and HTTP).
Intranet is a network that provides services within an organization that are similar to those provided by the Internet, but are not necessarily connected to the Internet. Intranets are typically protected by “firewalls” for security purposes. An intranet can be considered a private internet.
Web-based Applications on Internets and Intranets
Web-based applications can be flexibly deployed on both the Internet and intranets. For example, a Web-based airline reservations system on the Internet can be used to sell airline tickets to the public in a manner analogous to using a public 800 telephone number for similar purposes. In contrast, a Web-based groupware application for collaborative documents might be purposely restricted (via a firewall) to a corporate intranet to maintain the security of corporate information.
Web-based applications typically use Web browsers (e.g., Mozilla Firefox, Microsoft Internet Explorer, and Apple’s Safari) as a platform and HTTP as an additional Internet protocol.