===== Modem =====
[[dido:public:ra:xapend:xapend.a_glossary:start| Return to Glossary ]]

A **Modem** Modems (__mo__dulators-__dem__odulators) are used to transmit digital signals over analog telephone lines. Thus, digital signals are converted by the modem into analog signals of different frequencies and transmitted to a modem at the receiving location. The receiving modem performs the reverse transformation and provides a digital output to a device connected to a modem, usually a computer. The digital data is usually transferred to or from the modem over a serial line through an industry standard [[dido:public:ra:xapend:xapend.a_glossary:i:interface|interface]], RS-232. Many telephone companies offer DSL services, and many cable operators  use modems as end terminals for [[dido:public:ra:xapend:xapend.a_glossary:i:identification|identification]] and recognition of home and personal users. Modems work on both the Physical and Data Link layers.

Source: [[https://blog.netwrix.com/2019/01/08/network-devices-explained/ ]]