This meaning refers to systems that convert voice into digital data and transmit it using internet protocols.
The company replaced its old phones with VoIP.
VoIP can reduce the cost of international calls.
This use refers to a service, application, network, or business phone setup that uses internet telephony.
The office installed a cloud-based VoIP system.
Their VoIP includes voicemail and call forwarding.
This broader use refers to a voice conversation carried over an internet-based system.
We held the meeting by VoIP.
The connection remained clear throughout the VoIP call.