Final answer:
Local TV stations that are supplied with programming by a single television network are known as affiliates. These affiliates enter into agreements with networks to air programs at scheduled times, often including popular shows and national news, though they may diverge for emergencies. This system ensures viewers have access to a wide range of consistent national content.
Step-by-step explanation:
Local TV stations to which a single television network supplies programming and services are known as affiliates. Affiliates have agreements with networks to give priority to their news and programming. Networks like ABC, CBS, NBC, and Fox provide the majority of programming to these local stations across the United States, including popular shows and live sports events. Before the advent of cable technology, networks relied on local affiliates to transmit their programming using the affiliate's transmission towers, which have a limited radius. This was essential to ensure national network programming reached viewers in each major city. Today, while cable and fiber optics have reduced aerial signal dependency, affiliates still play a critical role in delivering content to audiences who use antennas or do not subscribe to cable services.
Television programming is varied and can be scripted, unscripted, or informative. National networks purchase rights to programs from television production companies, which they then distribute to affiliated local stations. This arrangement ensures that viewers receive a consistent schedule of programs from the national networks, despite the regional broadcast by the local affiliates.