An intranet is an internal website that companies use to manage communication, information and documentation. It is only open to employees of that company.
Intranets are built on various types of software, but the big one is SharePoint.
Why should you have an intranet?
Because how else will you communicate with employees? Email will only get you so far, especially if you are planning on expanding your business and making millions. And then there’s the documentation side. Of course there is Dropbox and Google Docs, we use a blended model of SharePoint (via Office 365) and Dropbox here. But SharePoint just offers so many more management features like versioning, categorization, alerts and instant reporting.
Having an intranet in the cloud means if you lose a laptop, it’s no big deal. Get a new one, change your password and you’re good to go; business as usual. Storing all your data on the C-drive of your computer is a huge business risk and creates ugly bottlenecks. A well designed intranet makes all that go away.