The Wi-Fi fencing is a technique that uses Wi-Fi SSID to define the fence. Whenever the user device gets connected to the defined SSID, the Wi-Fi fence triggers and then the selected restrictions in that Wi-Fi fence are applied on the device. While creating a Wi-Fi fence, you can provide any Wi-Fi SSID, and in addition you can select only the existing SSID from Wi-Fi configuration list.
Note: The new SSID which is added while creating a Wi-Fi fence, will not be the part of Wi-Fi Configuration. The Wi-Fi fence will be triggered only after the authentication process.