Best way I can describe it that makes sense in the simplest way is you're basically using your TV like a "limited" computer. On a computer you open a web browser and go to YouTube or any of these streaming sites like Netflix, Hulu etc. and watch movies and shows. On a smart phone you download an application for each streaming service to do the same thing. A smart TV or older TV with one of the add-on "boxes" basically also does the same thing but they have the applications for each streaming service installed on the TV itself (smart TV) or on one of the add-on devices. And it all comes through your internet.
