It's one of the biggest changes we're seeing in software like Microsoft Office. Click here for a basic introduction.
In Microsoft's universe, some of the key tools are Outlook (the email and calendaring tool), SharePoint (a platform for creating online workspaces where colleagues can work together) and Yammer (an instant messaging tool).
Collaboration between two people is relatively easy – you can just sit around one screen or email documents back and forth. But with workgroups, something more sophisticated is needed. This is why Microsoft developed the Groups function.
Groups appear in Outlook, Yammer and SharePoint so that members of a team can collaborate regardless of which application they're using. When a group is created, they can be allocated a workspace in SharePoint that allows them access to all of the documents and other resources required fro the project. Messages sent to the group can be accessed from either Yammer or Outlook.
There's more information in a recent blog post titled "The Evolution of Email" but the idea is that we are moving away from simply emailing documents around but working in real time collaboratively.