For a course or activity, there are several ways to apply groups. Here are the three group modes:

• No groups: There are no groups for a course or activity. If students have been placed in groups, ignore it. Also, give everyone the same access to the course or activity.
• Separate groups: If students have been placed in groups, allow them to see other students and only the work of other students from their own group. Students and work from other groups are invisible.
• Visible groups: If students have been placed in groups, allow them to see other students and the work of other students from all groups. However, the work from other groups is read-only.

You can use the No groups setting on an activity in your course. Here, you want every student who ever took the course to be able to interact with each other. For example, you may use the No groups setting in the news forum so that all students who have ever taken the course can see the latest news.

Also, you can use the Separate groups setting in a course. Here, you will run different groups at different times. For each group that runs through the course, it will be like a brand new course.

You can use the Visible groups setting in a course. Here, students are part of a large and in-person class; you want them to collaborate in small groups online.

Also, be aware that some things will not be affected by the groups setting. For example, no matter what the group setting, students will never see each other's assignment submissions.