What is Modem:
A modem is a communication device that allows connection between computers and the Internet by transferring data over telephone lines, cables, coaxial cables, or fiber.
Modem is the Spanishization of the term modem, acronym in English for MODulator / DEModulator which means "emulator" and "demodulator", since the device encrypts and decrypts the information necessary for the connection with your Internet service provider.
There are at least two types of modem: external and internal. External modems are devices that connect to the PC without being incorporated into its operating mechanism and require their own power supply. The best known modem is the telephone. This is responsible for connecting the telephone line to the computer. The process is based on detecting the signal tone, dialing a connection number and establishing a link.
The internal modems are those that are incorporated in the computer or equipment to be connected; therefore, they feed off the energy of the equipment that houses them. These are usually made up of an expansion card that can have different connectors. Among them are the PCI Bus, ISA Bus and AMR ..
Difference between modem and router
There are computers that combine the modem and a router, but generally they are separated. The router It is a device that shares the connection with several devices. You can identify a router because it has several cable entries ethernet. A router it has a single IP address and is not able to connect to the Internet without a modem.
The modem is the device that makes the connection to the Internet possible.