Many people wonder, what exactly is the difference between intranet and extranet, because both of them are types of personal networks which grants access only for selected users. What is more, both are designed to make communication process easier and faster, as well as to simplify operations performed within the network. So, even if those two concepts may seem to look exactly alike, I will provide some further distinction to prove that they are completely different.
Intranet is a special type of private network and is mainly used for company internal purposes. It is somehow a platform which is used to make communication and data exchange processes possible within the borders of a company. In this case, any files or data exchanged between users are not accessible for people outside of it and not involved. It can serve various purposes accordingly to its design and expectations it must fulfill in a company. The intranet is created to make numerous operations performed in a company easier and quicker. The simplest example of a working intranet is one created in a small office, where we have few workstations and multifunction device, such as printer + scanner. By connecting the hardware together to make a network, users can easily exchange files and use a multifunction device at once. Of course this is a very simple network and it doesn't offer any custom-designed user interface accessible through the web browser.Credit: http://www.flickr.com/photos/jbarahona/
Intranet can be also available on the Internet. In this situation, in order to use the network resources, every user need to have his own login and password which he will use for the purpose of authentication. While using the local area network, those security procedures are not critically needed (especially when a company doesn't store any important data on the hard drives) or can be established only for groups of users or for users and administrator only. Precautions are not that necessary, because in case of LAN connection, one can be completely sure, that nobody from the outside can access personal and company files without permission. Take note that security in case of private networks is a huge issue and there are many book written about this problem.
It is important to remember, though, that while using intranet via the Internet, the network should be secured properly, because in case of any hacker attack or data stealing, consequences can be profound.
Extranet is a kind of extended intranet with additional possibilities. It allows to share some options and data with users from outside the company personnel, like for example delivery workers. Extranet is the platform allowing outside companies to communicate with a particular company, for example by using forms or questionnaires available only for delivery workers via the Internet. Thanks to that, there is a possibility to inform about some time limits or the amount of ongoing payments. What is more, by the usage of extranet, company can communicate with its subcontractors to send them some new orders and commissions or to obtain invoices. It is important to note, that the platform offers access only to those functions, that are strictly linked with outside entities. This security procedure prevents undesired users to have insight into private data and files stored in company’s intranet. The main idea of the extranet is to boost and automate a significant part of company’s operations. It is aimed mostly at saving time needed for cyclical activities like parts ordering or sending invoices.Credit: http://www.flickr.com/photos/sewanee/
Similarly as with intranet, extranet can be accessed via the Internet. As it was in described in the previous case, in order to browse the content of it, user must obtain authorization data like login and password from the company’s network administrators. One of the most common examples of extranet in use, known by many Internet users, is the possibility to observe the order realization status. Buyer thanks to this function can track his package and receive some basic data about its condition and localization. A library account accessible via the Internet is another great example of an extranet. You can log into your account and request a book – you have the access to the requesting feature (which is related strictly to readers) and you don't have any features regarding administrating the system (that's an intranet feature).
To summarize, the difference between intranet and extranet is rather obvious. The most important difference between those two kinds of network is the availability to access the network. It can be accessed only by workers in case of intranet, and by users and companies outside the particular enterprise while speaking about extranet. Besides that, both of these types of private network are used mainly to increase productivity and the flow of the information through the company. In most cases they are custom-designed to provide the company with what it exactly needed.