VoIP stands for Voice over Internet Protocol. It refers to the Packet switched network. VoIP is used to send the packets of voice over the internet from one party to another. Here, the packets are served on the basis of first come first serve which may affect the call quality.
While VoWiFi, also known as WiFi Calling, has emerged as a new capability for smartphones that allows a mobile user to use the same phone number and the same smartphone dialer interface whether making a call over the cellular network or over any WiFi network.