We know what the Internet is. But, do you know what Intranet means? We know that intra means in, internal, or within 
and we know that the Internet deals with getting on websites to access information.
Intranet is a computer network that shares information. It can be a small office that uses its own private website that only staff has access to. From there, events, industry news, and a knowledge base may be shared. When part of the website is used for client access via username and password authentication, that part of the site becomes part of an extranet. As it sounds, it opens up access to the outside. This is popular for stock brokers, web designers, and researchers who want to share their work with clients.
Should your company start an Intranet? Most likely, your staff is using Gtalk, IM, Facebook, email, and text messages to collaborate. If you work on a lot of projects together, having a whiteboard you can share may be helpful. That way, the project may open up with ideas that the group may post on their own time. Further, project management applications may be used to mark benchmarks and time sensitive goals. This will achieve a measure of accountability and a solid tracking system.
Intranets are also used by universities. It’s actually probably the best example as students may access the intranet to view their class schedules, what books they need to buy or rent, when the school has off for holidays, and any special events.
Keep in mind that an Intranet should be well-secured by a computer network firewall as its privacy is fundamental to the firm, school, agency, or other computer network.