In Britain the airwaves were nationalized, and the BBC was set up to run the public airwaves. The idea was that the Government knew how to best run what was a public asset. In order to support the BBC, TV Licensces were developed.
In the US the idea was that the airwaves were a public asset, so the government would License the broadcasters, and let the public decide what they want to watch using the free market. The FCC sells the liscense to broadcast on particular frequencies, and there are some requirements involved in keeping your liscense...(you have to run so much "educational" programing...though almost ANY kid show can count as "educational") and so much "community service" programing...(normally local politicians talking to bored TV anchors in interview shows on Sunday morning that nobody watches 'cuse most of us are either asleep or in church at that time) and they have to be part of the Emergency Broadcast System.
Beyond that, each TV station is an independent buisness. Most TV stations have joined up with a network (ABC, NBC, CBC, Fox, etc.) so they can get national news and national programs that attract more viewers. Not all have. Some are local and run things like Star Trek re-runs and old movies.
You just plug in your TV an run up your antenna. No taxes or liscense on the user. EVER. It is all paid for by advertising. Companies by ad time, and how much they pay is determined by how many people are watching the show. The money from the sale of advertising time is what the networks use to pay the overhead and buy new shows. Advertising pays for it all. When a station joins a network the network says "You can air our programing, but we reserve 1/2 the advertising spots". That way the local station can sell a few ads in the middle of a show, but the network is guaranteed their set of ads, and that money goes to pay for the production cost of the show.
In the old days tputting up your antenna got you the 3 networks, and PBS (our "public broadcasing system"...think BBC wannabes). In larger cities you would also have a couple of "independent" stations that ran sports and re-runs of old shows. Most of the independent stations are now owned by Fox or the UPN/WB network.
With cable it is different. If you want cable you have to pay for it. It runs about $35 a month for 100 or so channels, but you can get fewer channels for less, or more channels for more. You can also get special digital channels in High Def for people that have high def TV's. (It doesn't make any sense to buy a super ultra realistic high def TV and then just run a regular signal into it after all.) If you want to go all out you can get 300+ channels. You stil get ads on cable.
Some people do satilite TV...same thing as cable pretty much, same channels, roughly the same prices (they compete) except that you pull down the feed from the satilite yourself and pay the satilite company instead of the cable company, and you have a little dish on your roof.
There are also "premium channels" on cable and sat that cost extra.. like HBO. Ten or twenty years ago HBO was something worth having...they paid extra and got ALL the best movies before they went on broadcast TV or other cable stations, they had all the good boxing matches, and some shows they made themselves that were basicly soft core porn. Today there are lots of other "premium channels" (STARZ, ENCORE, etc.) and they are ALL bidding for the same set of really good movies...so HBO doesn't have nearly as much good stuff to fill time with; and the network has declined. Now they have lots of really cruddy old movies, the boxing isn't that good anymore, Bill Maher (a washed up comedy star who pretty much everyone agrees is an idiot) talking about politics... they still do soft core porn, except some of it is now gay. Every so often they do a FIRST RATE mini-series, like FROM THE EARTH TO THE MOON or JOHN ADAMS, to try and keep their brand respectable...but mostly it's crud these days.
One of the things that is killing HBO is pay per view. If you have cable you can just order a movie you want to see on pay per view.. (the cost goes on your monthly bill, about $4 or so). This has pretty much taken over the first run movies, etc. that used to be HBO's bread and butter. In the 70s or 80s movies went from the theater to HBO, not they go from the theater to DVD and Pay per view, so by the time they get to HBO everyone has seen them.
Pay per view was pretty much nothing but a porn distribution system for the first few decades, but the people behind the technology want to shed that reputation and are making all sorts of things available on pay per view, often for free, just to get people using the technology. Lots of Sci Fi channels shows, old movies, even "How To" and exercise videos. The idea is that at some point in the future people won't even bother with the TV schedule. They will be able to come home and just tell the TV "TV, I want to see Battlestar Galactica" and the latest episode will run for them, when they want it...for a small fee of course.
Early next year the broadcasters are going to digital signals too...you will still be able to get them over the air for free, but you will need a digital TV. IF you don't want to buy a digital TV you can just get a signal converter box and hook it on to your regular TV...the government is making coupons available to people that can't afford the $40 or so it costs to get one of these.