A Workgroup is a group of people who are working together on the same project. The members of such a group are usually (not always) located in close physical proximity to one another - typically in a single room. The computers that these team members use are also said to be belonging to the same workgroup.
The concept of workgroups makes it very simple to communicate to a group of relevant people at the same time. Most network operating systems support the and Clinics workgroup concept.