We use 'sections' to organize class groups. Within class groups, we use the 'group' function to facilitate collaboration such as group work, turning in group submissions, and group communication.
Organizing students by sections and groups means you can easily target information such as announcements and emails to certain students. You can restrict materials and content as well, so that students only see the information/quiz/submission box that they need. In addition, when grading, you can easily sort students to only see your students.
Creating groups
Creating groups and sections

Sections
When functional or system administrator creates a course in Brightspace, they also make the sections. Make sure you have an idea of how many sections and their titles well before the course begins.
Sections exist within a program and help manage the cohorts of students across their courses or modules.
Groups
Teachers can make groups in Brightspace. For teachers sharing a Brightspace course, it can be handy to organize students into to groups to manage announcements, materials, content, and assignments. This also keeps the space organized because the students will only see what they need to see and not messages from other teachers or materials for other students.
Students can belong to several different groups. This means within groups, you can organize students into smaller groups for discussions or projects. You can also manage the settings so that students sign themselves up to groups, for example, to choose a certain topic for a discussion or project.
How do you use groups?
Examples of working with groups

Assessing work
You can filter via section and group so that you only see certain students and their work.
Publishing an announcement or material for your group
Place a restriction on announcements or material so that only the students in your group see the message or information.