Voice over IP (VoIP) allows a voice conversation to be transmitted as internet traffic rather than as an ordinary voice call.
This means that callers can use Wi-Fi networks or their data plans to make these calls.
These two applications are called voice over Wi-Fi and voice over 4G or voice over LTE.
Operators are currently trying to move voice calls onto 4G, since it is a more efficient use of spectrum than 2G calls and the call quality offered in these calls is better, with calls connecting faster.
What chat apps use VoIP?
Voice over Internet Protocol