Modem

Back in the 1990s, almost all residential users accessed the Internet over ordinary analog telephone lines using a dial-up modem. Today, numerous users in underdeveloped countries and in rural areas in developed countries (where broadband access is unavailable) still access

The least expensive and most frequently used guided transmission medium is twisted-pair copper wire. For over a hundred years it has been used by telephone networks. In reality, more than 99 percent of the wired connections from the telephone handset to the local telephone

Like twisted pair, coaxial cable is made of two copper conductors, but the two conductors are concentric rather than parallel. With this construction and special insulation and shielding, coaxial cable can have high bit rates. Coaxial cable is quite common in cable television