Ans: We know that computers operate in the digital world, but telephone lines require a different method of transmission. The modem modulates the digital signal into a sine wave. This can be broadcast over a telephone line. The signal is transmitted over the line, until it reaches the IP hub. At this point, the sine wave is demodulated into a digital signal once more, and the connection with the internet is complete. Modems can perform this work at a variety of speeds, depending on the technology and availability of access lines.