As the name suggests, a computer modem is a device that helps modulate the digital signals passing between a computer and the Internet. It converts the computer’s digital signals into an analog form that can travel over telephone lines and vice versa. This process is necessary because the telephone network is built to carry analog signals.

A computer modem is typically installed inside the computer, in a slot PCI, Express, or USB. External modems, which plug into an open port on the computer, are also available.

Computer modems come in a variety of speeds, the most common of which are …