how to watch TV online can be setup a number of ways. But to do this will require an Internet connection and device with a web browser. Well start with an Internet connection first, since this is needed to do or watch anything online. For the home, a modem/router will be needed. Its best to have a dual-modem/router that allows both a wireless connection and wired (Ethernet Cable) connection.
Internet Connection: Modem/Router
Think Mbps (megabits per second) which is a measurement used to figure out how fast is ones Internet connection. Higher the connection speed, better the picture quality and overall performance.