INTERNET

The Internet is a network that is available to anyone with an Internet-connected device. It is a massive collection of networks sharing information publicly in the form of interlinked Web pages. Internet Protocol defines a site's unique location which most users see as a domain name or URL. The network is literally world-wide and is often referred to as the world wide web.

INTRANET

An intranet network is only available to a small group of people. Intranets are mainly used within businesses and organizations to provide access to files and applications among networked computers and servers. Intranets may or may not have access to the Internet. If an intranet does connect to the Internet, a firewall is used to prevent outside access to the intranet. The purpose is to allow people within the same company to share information over a local area network. It is sometimes referred to as a private Internet.

EXTRANET

An extranet is similar to an intranet, but is accessible via a Web portal. An extranet may be accessed from anywhere if the user has a valid user name and password. The purpose of this type of network is to allow collaboration and sharing of resources not only in-house but with a select group of outside users. For instance, businesses will use an extranet to allow customers to log in to provide input on projects. Another example is using aVIRTUAL PRIVATE NETWORKto allow employees to log in to the network when they're are not in the office.

MAIN DIFFERENCES

The main difference between the three is accessibility. The Internet is public while the other two are highly restricted. Home users, if they use one at all, would only use an intranet to share files between computers and typically use the Internet when searching for and sharing information. Businesses and organizations are the main users of both intranets and extranets in order to restrict access to confidential data.

Internet vs Intranet vs Extranet

Computer networks differ from each other depending on their topology. Each type of network has its own characteristics which provide desired level of service to the audience. There are three comprehensive types of networks, Internet, Intranet and extranet. Each network shares same communication technologies. They differ in terms of size, access levels and the nature of users.

Internet

Internet is a Public network with thousands of computers (servers and clients) interconnected to share information. Clusters of computer networks are interconnected to build the network spanning all over the world. There is no centralized controller to control communication. It relies on network devices and protocols (Ex routing protocols) previously agreed upon. Any user can access Internet through an Internet Service Provider (ISP). Generally, internet is unregulated and uncensored, but there are some countries with restrictions imposed on internet access to their citizen. Although there is no centralized entity to control, ICANN (The Internet Corporation for Assigned names and Numbers) manages Internet Protocol Addresses and Domain Names.

Intranet

Intranet is a Private network with a limited number of computers interconnected and controlled in a defined manner. Intranet is setup and controlled by an organization, to ensure secure and uninterrupted connection between members to exchange information more efficiently. Organization requirements may include sharing latest news updates, management information, organization changes, new policies and procedures etc.

Intranet is much like the Internet, but it is isolated from the external world. Firewalls are used to connect Intranet to the outside world when it has to be connected to Internet. It uses same protocols like TCP/IP. Size of the Intranet depends on the organization requirements. It may span over one building, one area, or one country. In addition, there are many multinational organizations maintain Intranets between countries using dedicated fiber optic connections. Communication efficiency between network devices is high since the bandwidth is fully assigned to a fixed number of users. There are no frequent traffic spikes, channel breakdowns or server offline situations in the Intranet. Intranet may be accessible through the Internet. There are techniques like VPN connection to provide secure connections in such situations.

Extranet

Extranet is part of an Intranet, which is also categorized as a Private Network. It is controlled and managed by an organization, to provide secure access to Intranet from the outside world. Many business organizations need their business partners and customers to connect to Intranet to enhance communication and efficiency. Since the Intranet permits only internal members to gain access, external members (partners and customers) use Extranet to access the network. System administration/management can decide which users should allow through Extranet. Generally, external users are given limited access over the Intranet.

Not only external users, sometimes members of the organization itself who may need to access the network over the Internet can use Extranet.

What is the difference between Internet, Intranet and Extranet?

When it comes to size of the network, Internet is the largest and consists hundreds of thousands of network devices and interconnections. Intranet size may span from hundreds to several thousands of computers. Extranet comes as a part of Intranet, so it is the smallest.

Internet is a public network. Intranet and Extranet are private networks.

Users can access Internet anonymously. Users should have valid username/password to access Intranet and Extranet.

Generally, Internet is unregulated and uncensored. But Intranet/Extranet is regulated by the organization policies.

In the nature of users, Internet has unlimited number of anonymous users. Intranet keeps limited number of predefined users who are internal members of the organization. Extranet users are mostly non-organizational users.

What is the difference between extranet and intranet?An extranet has a portal to the outside world, while an intranet is an entirely internal network. Both intranet and extranet technology operates with normal HTML functionality, including proprietary limited-access Web sites, e-mail and FTP capabilities. Intranets and extranets typically look like regular Web sites, but they can only be accessed by a specific user group; either entirely internal, or with restricted access for some external users.

Extranets still aren't open connections, though; extranet users require a logon and security certificate to access extranet functionality. Intranets and extranets by definition have different levels of security, and thus each technology is better suited to different types of applications.

The differences in technology affect security.By the very nature of the two technologies, intranet and extranet solutions are not equally secure. Intranet technology is completely secure, because it is entirely internal. Intranets are hosted on local area connections, or restricted behind a firewall. Intranets have no portals to the outside world, or they're no longer intranets; they become an extranet with an external portal. A given organization could have a series of both intranets and extranets to serve company needs.

Because extranet technology involves a portal beyond company resources, the extranet by definition is less secure. Advances in Internet security and encryption mean that extranets are still extremely secure; some sources estimate that extranet encryption could take hackers years to crack. However, the vulnerability is there, and that makes an extranet unsuitable for some applications.

Extranet technology serves a different purpose in business applications.Because extranet technology is less secure by nature, it tends to serve a different purpose in business applications from a network intranet. An extranet is typically used in business-to-business communications, giving business clients a convenient HTML-based point of contact.

Extranets can enable business clients to place orders, check supply inventories, peruse order histories, browse FAQs or help documents or perform other company-related interactions. Intranets are used more to exchange proprietary internal information in a secure setting, such as managing payroll, distributing human resources documentation or sharing data and collaborating within the company.

Who uses an intranet, and who uses an extranet?By definition, an intranet is restricted to users within a company, as an intranet has no external portals. Therefore, intranet users might include an executive team, accounting department, human resources department and even regular company employees. Depending on how an intranet is configured, different users might have access to different levels of information.

A company extranet, on the other hand, is designed as a way for a company to share data with external users. A company extranet may extend to vendors, suppliers, business clients and customers: The possibilities are limited only by the scope of the extranet. Each of these users requires a unique logon and security certificate, and extranet administrators can typically track extranet use through the security certificates.