Definition - What does Modem mean?
A modem is a network device that both modulates and demodulates analog carrier signals (called sine waves) for encoding and decoding digital information for processing. Modems accomplish both of these tasks simultaneously and, for this reason, the term modem is a combination of "modulate" and "demodulate."
Techopedia explains Modem
The most common use for modems is for both sending and receiving of the digital information between personal computers. This information used to be transmitted over telephone lines using V.92, the last dial-up standard, to an analog modem that would convert the signal back to a digital format for a computer to read.
Now, access to the Internet more commonly takes place using high-speed broadband modems.