Cable television is a system of providing television, FM radio programming and other services to consumers via radio frequency signals transmitted directly to people’s televisions through fixed optical fibers or coaxial cables as opposed to the over-the-air method used in traditional television broadcasting (via radio waves) in which a television antenna is required.
As in the case of radio broadcasting, the use of different frequencies allows many channels to be distributed through the same cable, without separate wires for each. The tuner of the TV, VCR, or radio selects one channel from this mixed signal. [Many VCRs have their own tuner (for direct TV reception) and a programmable timer (for unattended recording of a certain channel at a particular time).]

Cable television in the United States Cable television programming is often divided between basic and premium programming. Basic cable TV networks are generally transmitted without any scrambling or other special methods and thus anyone connected to the cable TV system can receive them. Basic cable networks receive at least some funding through fees paid by the cable TV systems for the right to include the network in its channel lineup. Most basic cable TV networks also include advertising to supplement the fees, due to their programming cost being greater than the fees paid by cable TV systems.
Premium cable refers to networks, such as HBO and Showtime, that scramble or encrypt their signals so that only those paying additional monthly fees to their cable TV system can legally view them (via the use of cable box). Because these networks command much higher fees from cable TV systems, their programming is generally commercial free.
Because cable television carries more bandwidth than broadcast TV (10 to 20 times as many channels), there is room for more specialized channels catering to particular demographics or interests. And, since cable TV channels cannot be viewed by those (e.g., children) without the proper equipment, the FCC’s rules regarding acceptable content do not apply to cable TV networks, allowing greater freedom in the use of profanity, sex and violence. Premium cable networks have traditionally been the loosest with regard to content; while there are no FCC rules that apply to content on basic cable networks, because most such networks rely at least partly on advertising revenue, they have buckled to pressure from advertisers to keep their content more in line with that of broadcast TV.
List of United States cable and satellite television networks