Can someone explain American tv to me?

Question

what is a 'network' channel, and what are the main channels/networks?

Answer 1

Network companies have various channels all over the country that are part of their network.  The channels are loyal to the hub - they play the programming of the home location but they also have local programming, like local news.  NBC is a network station. A network program for them is The Today Show.  But, if you notice, you also have local news available, usually in the AM, at noon, in the evening and at night.  The various stations (locations) are available to the main office. Often, they will use a local newscaster or meteorologist if one of the network people is absent for an extended period of time. They also use the local people in cases of bad weather as a way to stay on top of the details as they happen. They may send down one of the guys from the main office, but the local person will cover another area which may have a smaller population or less risk of becoming a major news story.

NBC, CBS, ABC, FOX.. these are network channels.

USA, TBS, TNT, SCI-FI.. these are cable channels. You won't find a USA local news, for example.

Answer 2

The Networks (CBS, NBC, ABC and Fox) have affiliates (hundreds of them) around the country that air the Networks shows.    

So the American version of the Office is an NBC show and my local affiliate (Channel 7 in Boston) airs it along with all other NBC owned shows.  The station also airs the NBC Nightly News which is the Network's country wide nightly news program.  The local station also airs Boston news programs with local news.   Same all around the country.. the NBC channel will be different in New York, Detroit, Peoria, etc... and they'll all have their own local news shows and programming along with the NBC owned shows.   NBC has 230 affiliates around the country.   ABC and CBS have similar number, Fox is newer and likely has less.

There are also syndicated programs which are not owned by any particular network, independently produced shows that any affiliate can purchase and air as they like.  So I might watch the Ellen Degeneris (I think she's syndicated) show on my CBS station, but someone in NY might watch on NBC.

Not sure if that helps or confuses things more!