Contrary to what Content Management System (CMS) sales and marketing forces around the world want you to believe, Internet, Intranet, and Extranet are not the same thing.  Pay attention I am only going to explain this once…  These business tools are not used or delivered in the same way, have different goals, and have different technological requirements.

You still need more of an explanation…  Lets start with some vocabulary.

Internet

The Internet is a global system of interconnected computer networks that interchange data by packet switching using the standardized Internet Protocol Suite (TCP/IP). The Internet carries various information resources and services, such as electronic mail, online chat, file transfer and file sharing, online gaming, and inter-linked hypertext documents.  The Internet is open to the general public. Wikipedia

Intranet

An intranet is a private computer network that uses Internet technologies to securely share any part of an organization's information or operational systems with its employees. Sometimes the term refers only to the organization's internal website, but often it is a more extensive part of the organization's computer infrastructure and private websites are an important component and focal point of internal communication and collaboration. An intranet is not open to the general public.  Wikipedia

Extranet

An extranet is a private network that uses Internet protocols, network connectivity, and possibly the public telecommunication system to securely share part of an organization's information or operations with suppliers, vendors, partners, customers or other businesses. An extranet can be viewed as part of a company's intranet that is extended to users outside the company.  An extranet is not open to the general public. Wikipedia

Let me see if I can further clarify…

There is only one Internet (notice the uppercase “I”. Some people will argue, correctly, that an intranet is just interconnected computers and these internets are not public domain nor are they necessarily connected to each other.  I am not talking about that internet (lowercase “i”))  Anyway, I digress… there is only one Internet.  This is the public computer based advertising and selling arm of your company.  This is where you interact with “John Q. Public”.

Your companies intranet is where you post all the juicy little bits of information you don’t want other companies and “John Q. Public” to know about.  HR policies, internal procedures, inventory controls, cost structures, financial data, and the company newsletter all are perfect candidates for your intranet.

Your companies extranet is where you allow someone from a trusted external company to authenticate themselves and then gain access to selected information about your company.  WalMart is using an extranet to allow suppliers to check the inventory levels for the external companies products at each of its stores.  This is not open to the public.  You have to provide secure methods of connecting and authenticating.  Can you imagine what would happen if Huffy found out Schwinn bicycles login?  Or if one supplier found out the cost of another competing suppliers product? 

So, when that sales person tries to sell you on the fact that their CMS is capable of handling your Internet, Intranet, and Extranet content take a moment and think about that claim.  Can they really control access to your most private business secrets on the same system that holds your publicly accessible Internet content?  What would happen to your company if your competitor or even a supplier got into the wrong area?  Invite your IT staff to the meeting and let them ask the technically specific questions about how the CMS system will work.  Then listen to your IT staff about their concerns before deciding on a CMS provider.