It basically applies to any TV being watched as it is being broadcast at the time so you are liable to pay anything if you only watch shows after they have been aired.
Myself I tend to watch Netflix, some iPlayer and 4OD stuff and I do not have to pay anything.
That doesn't stop them sending letters once in a while to check though.
The BBC is the only recipient of TV license fees in the UK - of course after plenty of cost created on the way between the consumer / license payer to the BBC / payee.
BTW the BBC is also the TV licensing authority in the UK and is authorised by the government via the Communications Act 2003 to collect and enforce the TV license fee. One of the companies in the Capita conglomerate has been "entrusted" by the BBC / the government to collect the TV licensing fees.
A lengthy correspondence with them led them to conclude that because my TV was not connected to a TV aerial or cable, and I only used it to watch Netflix and iPlayer from my computer, I did not in fact need a TV license.
I've been through this dance with them three or four times.