The Virtual Fence / Geo-Fence feature has two alert options: In-Fence and Out-Fence.

In-Fence alerts you when your baby moves into the selected area.
 

Out-Fence alerts you when your baby moves out of the selected area.

You can choose the option that works best for your setup. For example, you may use Out-Fence when you want to know if your baby leaves a safe area, or In-Fence when you want to know if your baby moves into a certain area.