Voice over IP (VoIP) is a technology that allows people to make phone calls using the internet instead of traditional telephone lines. It converts sound into digital data, which is then transmitted over the internet. This method can reduce costs and provide additional features like video calls and messaging. VoIP services can be used on various devices, including smartphones, computers, and specialized VoIP phones. Popular VoIP applications include Skype, Zoom, and WhatsApp. By using the internet for communication, VoIP can offer more flexibility and convenience compared to conventional phone systems.