A Geo-Fence is a circular area defined by the user. This area is used as a reference to determine if a Geo-Device (e.g., a mobile device associated with the account) is inside or outside this area. Based on this, it is possible to create automation rules, reminders, and notifications.

For example, a thermostat can be set to specific temperatures based on whether the Geo-Device is inside or outside the radius of the Geo-Fence.
 

Note: The minimum radius is 1.6 kilometers (or one mile), and the maximum is 160 kilometers (or 100 miles). If your account is in Canada, the minimum distance is 3 kilometers for a Geo-Fence.