In simple terms, whatever a user can do with the Internet he should be able to do within an organization's private network or intranet 
Intranet technology helps companies disseminate information faster to both vendors and customers and can be of benefit to the internal operations of the organization. Intranets have attracted a lot of attention in a very short time.
The intranet uses Internet and Web technologies to solve organizational problems traditionally solved by proprietary databases, scheduling and workflow applications. One should understand that an intranet is different from a (LAN) local area network or wide area network (WAN), although it uses the same physical connections. An intranet is an application or service (or set of applications or services) using the computer networks (the LANs and WANs) of an organization and that is why it is different from LANs and WANs. The intranet is only logically internal to the organization.
Intranets can physically span the globe, as long as access is specifically defined and limited to the specific organization's community of users behind a firewall or a series of firewalls.
In a typical intranet configuration, all users in the organizationcould access all the Web servers. The system administrator must define the degree of access for each user. They can constantly communicate with one another and post information on their departmental web servers. However, usually a firewall (or several firewalls) separates these internal networks from the world wide web.
Within these departmental Web servers, individual employees can have their own Web pages broken down by department and a series of Web pages. For example the following departments each may include several Web
pages as parts of the organization's intranet program:
- Human resources,
- Information services,
- Marketing and Sales.
Information architecture requires a company to make decisions as to who has access to what. Intranets and extranets are systems designed to address these issues.An intranet is a network based on TCP/IP protocols belonging to an organization, usually a corporation, accessible only by the organization's members, employees, or others with authorization. The website of an intranet looks and acts just like any other Web sites, but the firewall surrounding an intranet fends off unauthorized access.
Corporate Intranet: Different users, such as employees and/or customers, can make annotations on the same Web document and share ideas.