Groups are a function in SOL that you can use to organise your students across a unit/site into discreet groups. Once you've done this, you can choose to apply these group associations to many items in SOL to enhance the student experience, such as forums or wikis, or to aid administration of large cohorts with multiple tutors in assignments.
It is easy to create groups, add students to them, and apply these groups to items, and doing so will not affect any parts of your SOL site or your students' experience unless you ask it to.
You can create as many groups as you like in a given SOL site, and students can be put in more than one group. You have extra control of how you use these extra groups with the Grouping function (see Grouping chapter).