Modem is short for modulator and demodulator. Modulator serves to make the process of laying the data on the carrier signal to the information signal to be sent to the user through a particular medium, this process is usually called the modulation process. in this process the data from the computer in the form of a digital signal is converted into an analog signal. While Demodulator serves as the process of getting back the data sent by the sender. In this process the data will be separated from high frequency and data in the form of analog signals are converted back into digital signals that can be read by a computer.