The Groups feature enables lecturers and Programme Administrators to assign students to one or more groups. There are three ways of assigning students to group on a module:
You can assign different group modes to activities within Moodle to shape how that activity behaves. For example:
Within activities and resources, selecting Group under the Restrict access option in the activity/resource settings can be used to restrict which group can access this content. By default, the activity or resource will be visible to all students but only accessible to those in the group. If you want the activity or resource to be hidden completely from students who are not in the relevant group, select the eye next to Group to hide it.There are four levels of visibility available for groups.
Groups/Groupings and extensions and resubmissions
If you are using groups to manage extensions and resubmission you must set up a Hidden group. Do not use any other group visibility options.
Groups that are Hidden or set to only see own membership cannot be used by staff to filter an Assignment for marking. This is expected behaviour. Ensure groups are set to visible if you want to use them to filter assignment submissions for multiple markers
Groupings are collections of groups. If a student is in more than one group, or you want a subset of groups to work on a specific activity (e.g. a group assignment) you will need to use Groupings for the Groups to work correctly on the activity.

This scenario below provides an insight into how Groupings works.
How does the lecturer want the groups activity to work?
In Moodle, the lecturer wants to create a collaborative workspace using a Forum for each Project Group to communicate with their Project Group.
Groups available on Moodle:
Tutor Group 1
Tutor Group 2
Project Group A
Project Group B
Project Group C
Project Group D
Groups Joe Bloggs belongs to:
Tutor Group 1 & Project Group B
Group/grouping settings required:
Set up a Grouping called Project Grouping and add the following groups:
Project Group A
Project Group B
Project Group C
Project Group D
Under the Common module settings option in Forum settings, apply separate group mode and select Project Grouping.
Result
Each Project Group has its own collaborative workspace. If you had not set up Groupings in this scenario, Moodle would have no way of knowing which groups needed to be attached to the Forum. Joe Bloggs would have had access to two Forums - one for Tutor Group 1 and one for Project Group B!

