You can set up an unlimited number of geozones in your account and when devices travel into or out of those zones you can elect to be notified. Trucking companies want to know when their shipment leaves their customer's warehouse , arrives at their DC and then arrives at the retail store. Geozoning provides this. Plug in any address and determine the radius you wish to have for the zone. There is no limit to how small you can make the geozone but GPS locates can ping around several hundred feet so the smaller the geozone is the more chance there is of a false geozone exit or entry alarm.
Watch the geozone tutorial