Service territories help you organize your workforce. They typically represent geographical areas where your teams work.

Create a Service Resource and Dispatcher

After creating a new user, James Clifton, I am able to head to Field Service Settings > Create Service Resources and add that user with his own service territory, licenses, and permissions.

Lastly, I can make myself a dispatcher for the Los Angeles service territory to start assigning work to James.

I do this by adding Permission Set Assignments to my user.