What a user group is
A user group is a named set of permissions — which departments, locations, incident types and features a member of that group can access. Instead of setting permissions per person, you set them once per group and assign people to it.
Creating a group
Go to Settings → User Groups → Add group, give it a name that describes the role (for example "Site Supervisors" or "Medical Team"), then choose which locations, departments and incident types it should have access to.
The permissions you can set
A group's permissions cover which locations and departments it can see incidents for, which incident types it can create or edit, and which features are available to it (for example, whether members can export reports or manage other users). Keep groups as narrow as the role actually needs — it's easier to widen access later than to work out what to remove.
Assigning a user to multiple groups
A user isn't limited to one group — someone covering two roles (say, a supervisor who also handles medical incidents) can belong to both groups, and gets the combined permissions of each. Add or remove a user's groups any time from their profile in Settings → Users.