'modem' originates from the combination of 'modulator' and 'demodulator', where 'modulate' means 'to adjust or regulate' and 'demodulate' means 'to extract the original information-bearing signal'.

'Modem' was coined in the mid-20th century as a portmanteau of 'modulator' and 'demodulator'.

Initially, it referred specifically to devices used for telephone line data transmission, but now it includes various types of data communication devices.