In order to define zones we will go to:
Access Control → Configuration → Areas/Enclosures
In the next window we can either create a new zone with the button "New", edit one of the existing zones or delete one of them.
If we click on the button again to create a new zone we will see the following window, where we will enter the name and if we want a description about the zone.
Instead, if we click the edit button, the following window will open, where we can edit the name and description.