Breakout rooms can be added to Teams Meetings. Breakout rooms are a useful option for splitting a large meeting into small groups for discussion. Only meeting organizers can create and manage breakout rooms in Teams. 

To learn more about joining and collaborating in breakout rooms as a meeting participant please see Microsoft's article, Join a breakout room in a Teams meeting. 

To learn more about breakout rooms in Teams and how to set them up as a meeting organizer please review Microsoft's article, Use breakout rooms in Teams meetings.

Breakout Rooms Button on Meeting Organizer's Toolbar 

Create Breakout Rooms Window