what is modem and it's type ?
A modem is a hardware device which means modulator-demodulator.
modems are used to transfer data from one computer network to another computer network through telephone lines.
the computer network works in digital mode, while analog technology is used for carrying messages across phone lines.
the modulator converts information from digital mode to analog mode at the transmitting end and demodulator converts the same from analog to digital at receiving end.