The function of Groups is to help categorize a users's working roles within your setup. While this sounds fairly similar to Departments, there is a distinct difference between the two, not only in semantics but in functional purposes as well.
The main differences between Groups and Departments are:
- A group represents a functional purpose. Thus, a user can belong to many groups but can only belong to one department.
- Groups are usually agnostic from an organizational structure viewpoint. Lets say, for instance, that an organization has 10 departments and each department has a secretary. In this case, Secretary would be a group in itself and the members of the Secretary group would all belong to different departments.
In short, use Departments when you are trying to represent a user's placement within an organizational chart, and use Groups to represent the various functions a user might carry out.
Figure 1: Users - Setup Groups
To manage groups, go to Users > Setup Groups.
Note that each group created can be tied to a specific organization, although not necessarily so. As mentioned earlier, a user can belong to multiple groups and, unless restricted, a group can have members that span several organizations.