Input and output of a modem?

A modem (modulator-demodulator) converts digital data from a computer into analog signals for transmission over telephone lines or other communication media (modulation) and vice versa (demodulation). The input of a modem is typically digital data from a device like a computer or router, while the output is an analog signal suitable for transmission. Conversely, the input received by the modem is an analog signal from the communication medium, which it converts back into digital data for the receiving device. This process enables internet connectivity and data communication over various types of networks.