If you haven't already, visit your Activity page and click on the carrot next to your company name. A drop down menu will show examples of teams, like Business. You can click on a suggested team to create it, or click "Add a Team" to type in a new name.
Teams can have separated integrations.
For example, if you use the post to chat integration for Slack, your Marketing team can set up one Slack channel, and your Design team can set up another.
Your coworkers will only receive email updates for their team.
For example, if you're on the Content team, you'd only receive an email with posts from other people on the Content team.
If you don't have any teams set up, everyone is effectively on the same team, so you'll receive all updates.
Be aware: updates can be seen by anyone within the account, not just other people on the team.
Everyone joined under the same account will be able to visit any other teams and see all their updates by selecting the company's name from the team list.
For example, if WorkingOn is the company, when WorkingOn is selected, I see a feed with everyone's updates. If I select the Finance team, I'll only see Finance updates.