Students may be placed in Groups within a course. They can then be used to limit shared activities, like Forums, to the smaller groups, rather than the entire class. The specifics of how Groups actually work is very dependent on the type of Activity, Resource, or Group Mode that is used. Groups can be used on both the Course level and the Activity level. One important item to remember is that using a Group Mode allows the exact same resources or activity to be presented to groups in a course for smaller working groups. The key concept is that the materials and activities are the same for each group. Here are some common uses of groups taken from the https://docs.moodle.org/37/en/Groups:
Please see Assignment Restrictions for details about using groups to restrict access to Assignments. For other activities, resources, and topics areas, use the Restrict Access section to add restrictions based on group membership, among other criteria.
Under Administration goto Course Administration>Users>Groups
Click Create group
Give the group a name and complete the Create group canvas.
Back in the groups listings, highlight the group you want to add members to by clicking on it, and click Add/remove users.
Under the Potential members list, choose the members you want to add to group. You can hold shift down to select multiple users in a row or CTRL(Windows) or Command(Mac) to pick random users. Highlight the users and click Add.
Your users will be moved over to the Group members field. You can click Back to groups.
You will then see your groups listed and when you click on the group the associated members will show up in the right-hand field.
Once you have your groups set up, you need to do one last step and set your course to handle Separate Groups.
Under Administration goto Course administration>Edit Settings
In the Edit settings, find the Groups section and click on "Groups" to expand the sections. Change the Group mode to Separate groups.
Save your changes.
Once groups are established, you will be able to filter your gradebook to show only a certain group.
Send email via Quickmail to specified groups
As well as set up submission settings within group assignments.