Over recent years, the terms intranet and extranet have established themselves firmly in the IT vocabulary. Even so, many people are still unsure about what exactly defines, or is defined by, either an intranet or an extranet. IntranetsThe term intranet is commonly used to describe a web-based application or system that provides tools for groups of people to work together collaboratively. The key element of an intranet is that only people within an organization can access it. Intranets are typically hosted, maintained, and operated completely independently from an organization's external Web presence, even though some of the information provided through both mechanisms might be the same. An example of an intranet is shown in Figure 8.4 Figure 8.4. An example of an intranet.
Intranets are commonly identified by the following characteristics:
ExtranetsAny network or application that is accessible from outside the physical and logical boundaries of an organization can be called an extranet. This means that any network on which remote access services are provided could, technically, be considered an extranet. Commonly, though, the term extranet is used to describe a system or application, hosted within an organization, which is securely made available to selected individuals or entire organizations outside of the hosting organization. The key consideration to this model is that the company providing the system controls access to the extranet. In other words, only selected clients and associates are provided with access, and they might even be required to access the extranet over secure virtual private networking (VPN) links. Contrast this with the model used by, for example, online bookstores, where anyone can access the site, even though a username and password is subsequently required to place or track orders. Although the bookstore could decide to prevent a certain user from accessing the site, they are unlikely to do so. Figure 8.5 shows an example of an extranet. Figure 8.5. An example of an extranet.Extranets are commonly identified by the following characteristics:
Typically, though not exclusively, extranet applications, like intranet applications, are hosted on a Web server and accessed through a Web browser. |