Computer-phone link is a technology that allows computers and phones to be connected together. This connection is made possible by a modem, which is a device that modulates and demodulates signals between two digital devices. The modem is the key component in establishing a computer-phone link, as it converts the digital signals from the computer into analog signals that can be transmitted over telephone lines. This technology has enabled people to access the internet from their phones, as well as make phone calls from their computers.