(1) Typically these are Smart TVs, televisions with built-in connection to the internet and other ways to be interactive such as using an OTT (Over-the-Top) mechanism. The user is able to connect to the outside world and interact through the TV, and if applicable that which is associated with the TV.

Bing Definition
Google Defintion

(2) A TV channel used to list or promote programs on other channels.

(3) Internet-connected TV.