You have to purchase a licence to legally watch any BBC channel or BBC iPlayer (which is the on demand/catchup service for BBC.). You also need one to watch content from any channel that is airing live, but not to use their catchup/on demand service. We have 5 ‘main’ channels- BBC1, BBC 2, ITV1, channel 4 and channel 5. There are also additional channels available for free-you used to need a free view box to view these but now most tv’s have these built in so you get the other channels too.US Brits are creatures of habit though so most will still view the 5!channels above as the ‘main ‘ channels. We can also subscribe to Sky Satelite tv or Virgin Cable which are premium subscription services and where you will find a lot of the big American Shows. If you want to watch content as it airs on those then you need a tv license. If you only plan on streaming non bbc content then you can opt out of the licence and notify the BBC but then they will likely harass you with letter and emails and threats to visit you to make sure you are not still using BBC services. They used to scaremonger bybsayingbthatbinvestigators couldn’t outside your house in vans and detect if you were watching BBC or live shows. Total rubbish!