Groups are a way to bring a selection of people together. Groups are useful as you can assign content to groups and also you can filter reports by the group.
We recommend groups being used for temporary groups of people that are unrelated by hierarchy. For instance a cohort of new starters or the delegates from a leadership programme or your SLT.
You may have a group for a Leadership Programme and want them to complete specific modules or content, you can assign the content to that group.
For permanent groups of people like departments, we recommend you use User Fields