Normal calls made over devices are over 2G and 3G networks. VoLTE and VoWIFI (Wifi Calling) are both features that enable you to place HD calls on your Cat device.
VoWIFI and VoLTE are data-only networks, where both voice and video are sent as data from one point to another phone.
Note: Both VoLTE and VoWIFI are features that need to be activated by your network provider.
The VoLTE feature is based on the 4G network and allows you to make high-quality calls or video calls over a 4G network.
VoWIFI is similar to VoLTE in that this feature enables you to place an HD call or video call but over a WIFI connection.
If VoWIFI is enabled, and your Cat device is connected to a WiFi network, you will be able to make voice or video calls including if there is no mobile network available.