Digital rights management (DRM)
Digital Rights Management or DRM is a way of protecting files like TV programmes from being copied.
It works automatically whenever you download a programme from the internet.
It's a bit like borrowing a book from a library, you can have the programme to watch for a little while, but you can't keep it forever. The reason is that the writers and performers who made the programme actually own the rights to it, but there is an agreement which means that you can have your own copy for a limited period to watch at home.
Just like a library, you need to register for this to work. After you have registered by making up a username and password, you can borrow things whenever you like. After a certain amount of time, usually about 30 days, the programme will be deleted from your computer, although you always get plenty of warning before that happens.
If you start to watch a programme, you can stop at anytime and come back to it later, although programmes which have not been watched at all can usually be kept for longer.